Open access article in Acta Crystallographica Section C: Crystal Structural Communications

(E)-3-(Benzo[b]thiophen-2-yl)-2-(3,4,5-trimethoxyphenyl)acrylonitrile and (Z)-3-(benzo[b]thiophen-2-yl)-2-(3,4-dimethoxyphenyl)acrylonitrile. Corrigendum

Sonar, V.N. — 2013-04-15

The chemical names of the title compounds in the paper by Sonar et al. [Acta Cryst. (2007), C63, o743–o745] are corrected.

Two new XP(O)[NHC(CH3)3]2 phosphoramidates, with X = (CH3)2N and [(CH3)3CNH]2P(O)(O). Corrigendum

Pourayoubi, M. — 2013-04-15

The chemical name of one of the title compounds in the paper by Pourayoubi et al. [Acta Cryst. (2012), C68, o164–o169] is corrected.

A three-dimensional tin(II) phosphonatobenzenesulfonate with Sn4O12 clusters. Corrigendum

Maniam, P. — 2011-06-15

An error in the scattering factors in the paper by Maniam & Stock [Acta Cryst. (2011), C67, m73–m76] is corrected.

Bis(2,4-pentanedionato)cobalt(II)

Burgess, J. — 2011-06-15

The structure of Co(acac)2 reported by us [Burgess et al. (2000). Acta Cryst. C56, 649–650] has been reassessed in view of a recent article [Vreshch et al. (2010). Inorg. Chem. 49, 8430–8434], which suggests that the compound might actually be Cu(acac)2. Using the structure-factor data deposited with the original article, the evidence is slightly in favour of Cu(acac)2, although the crystallographic data alone, in this case, cannot unequivocally distinguish between the two possibilities. We concede that we may indeed have been mistaken, but that there is still some element of mystery.

N-{N-[2-(3,5-Difluorophenyl)acetyl]-(S)-alanyl}-(S)-phenylglycine tert-butyl ester (DAPT): an inhibitor of γ-secretase, revealing fine electronic and hydrogen-bonding features

Czerwinski, A. — 2010-12-15

The title compound, C23H26F2N2O4, is a dipeptidic inhibitor of γ-secretase, one of the enzymes involved in Alzheimer's disease. The molecule adopts a compact conformation, without intramolecular hydrogen bonds. In the crystal structure, one of the amide N atoms forms the only intermolecular N—H⋯O hydrogen bond; the second amide N atom does not form hydrogen bonds. High-resolution synchrotron diffraction data permitted the unequivocal location and refinement without restraints of all H atoms, and the identification of the characteristic shift of the amide H atom engaged in the hydrogen bond from its ideal position, resulting in a more linear hydrogen bond. Significant residual densities for bonding electrons were revealed after the usual SHELXL refinement, and modeling of these features as additional interatomic scatterers (IAS) using the program PHENIX led to a significant decrease in the R factor from 0.0411 to 0.0325 and diminished the r.m.s. deviation level of noise in the final difference Fourier map from 0.063 to 0.037 e Å−3.

Two isomorphous crotonatolanthanide complexes: tetra-μ-but-2-enoato-bis[diaqua(but-2-enoato)Ln]–2,6-diaminopurine (1/2) (Ln = Dy and Ho). Corrigendum

Atria, A.M. — 2010-07-15

One of the figures in the paper by Atria, Astete, Garland & Baggio [Acta Cryst. (2009), C65, m411–m414] is corrected.

μ2-Acetato-κ2O:O′-tris(μ2-ferrocenecarboxylato-κ2O:O′)bis[(N,N-dimethylformamide-κO)copper(II)]. Corrigendum

Luo, J.-H. — 2010-04-15

In the paper by Luo, Huang, Huang & Wang [Acta Cryst. (2008), C64, m121–m122], the structure reported as [Cu2Fe3(C5H5)3(C2H3O2)(C6H4O2)3(C3H7NO)2] is actually a cocrystal in which one of the ferrocenecarboxylate ligands in about 16% of the molecules has been replaced with acetate. The correct structure of [Cu2Fe3(C5H5)3(C2H3O2)(C6H4O2)3(C3H7NO)2]0.84[Cu2Fe2(C5H5)2(C2H3O2)2(C6H4O2)2(C3H7NO)2]0.16 is now reported.

Strontium tetrafluoroborate. Erratum

Goreshnik, E. — 2010-03-15

In the paper by Bunič, Tavčar, Goreshnik & Žemva [Acta Cryst. (2007), C63, i75–i76], the structure reported as Sr(BF4)2 is actually that of Cd(BF4)2. The correct structure of Sr(BF4)2 is now reported.

The zwitterion of 4-nitro-2-{(E)-[2-(piperidin-1-yl)ethyl]iminomethyl}phenol

Santos-Contreras, R.J. — 2009-01-15

The title Schiff base compound, 4-nitro-1-oxo-2-{(E)-[2-(piperidin-1-yl)ethyl]iminiomethyl}cyclohexadienide, C14H19N3O3, exists as a zwitterion, with the H atom of the phenol group being transferred to the imine N atom. The C=O, CAr—CAr and C—N bond lengths are in agreement with the oxocyclohexadienide–iminium zwitterionic form. The iminium H atom is engaged in a strong intramolecular hydrogen bond with the O atom of the keto group (N+—H⋯O) to form an S(6) motif. Soft C—H⋯O interactions in the ac plane lead to the development of hydrogen-bonded tapes, which are π-stacked through the oxocyclohexadienide ring and iminium group. The significance of this study is in providing crystallographic evidence, supported by NMR and IR data, of the predominance of the oxocyclohexadienide–iminium zwitterion form over the noncharged canonical form in the title Schiff base.

Imidazolium-based ionic liquid salts: 3,3′-dimethyl-1,1′-(1,4-phenylenedimethylene)diimidazolium bis(tetrafluoroborate) and 3,3′-di-n-butyl-1,1′-(1,4-phenylenedimethylene)diimidazolium bis(trifluoromethanesulfonate)

Ganesan, K. — 2008-09-15

Crystallization of the ionic liquid 3,3′-dimethyl-1,1′-(1,4-phenylenedimethylene)diimidazolium bis(tetrafluoroborate), C16H20N42+·2BF4−, (I), from its solution in water has permitted the first single-crystal study of an imidazolium-based ionic liquid having a tetrafluoroborate ion as counter-ion. Despite the expectation that the anion would not participate in nonclassical hydrogen bonding, the ionic liquid features C—H⋯F hydrogen bonds. The dication lies about a center of inversion. The ionic liquid 3,3′-di-n-butyl-1,1′-(1,4-phenylenedimethylene)diimidazolium bis(trifluoromethanesulfonate), C22H32N42+·2CF3SO3−, (II), features both C—H⋯F and C—H⋯O hydrogen bonds.

Setting ambiguity in C2/c with dibromidotetrakis(1H-pyrazole-κN2)manganese(II) as an example. Addendum

Ruth, K. — 2008-05-15

In the paper by Ruth et al. [Acta Cryst. (2007), C63, m566–m569], remarks regarding the results of Bolotina et al. [J. Appl. Cryst. (2003), 36, 1334–1341] are withdrawn.

Accurate stereochemistry for two related 22,26-epiminocholestene derivatives

Vega-Baez, J.L. — 2008-04-15

Regioselective opening of ring E of solasodine under various conditions afforded (25R)-22,26-epiminocholesta-5,22(N)-diene-3β,16β-diyl diacetate (previously known as 3,16-diacetyl pseudosolasodine B), C31H47NO4, or (22S,25R)-16β-hydroxy-22,26-epiminocholesta-5-en-3β-yl acetate (a derivative of the naturally occurring alkaloid oblonginine), C29H47NO3. In both cases, the reactions are carried out with retention of chirality at the C16, C20 and C25 stereogenic centers, which are found to be S, S and R, respectively. Although pseudosolasodine was synthesized 50 years ago, these accurate assignments clarify some controversial points about the actual stereochemistry for these alkaloids. This is of particular importance in the case of oblonginine, since this compound is currently under consideration for the treatment of aphasia arising from apoplexy; the present study defines a diastereoisomerically pure compound for pharmacological studies.

Lupulin structures revisited

Molins, E. — 2009-03-15

The crystal structures of lupulin A, C30H46O11, and lupulin D, C25H38O8, should both display the neoclerodane skeleton, but the deposited atomic coordinates of lupulin D correspond to the inverted enantiomer.

A novel heterocyclic compound: catena-poly[[[diaquasodium(I)]-di-μ-aqua] hemi(1,5-dihydroxy-4,8,9-trioxa-2,6-diazabicyclo[3.3.1]nona-2,6-diene-3,7-diolate)]. Retraction

Fang, R.-Q. — 2008-02-15

The paper by Fang et al. [Acta Cryst. (2007), C63, m193–m194] is retracted. It has subsequently been shown that the crystal studied was borax.

Carbonyl–carbonyl, carbonyl–π and carbonyl–halogen dipolar interactions as the directing motifs of the supramolecular structure of ethyl 6-chloro-2-oxo-2H-chromene-3-carboxylate and ethyl 6-bromo-2-oxo-2H-chromene-3-carboxylate

Santos-Contreras, R.J. — 2007-04-15

The title compounds, C12H9ClO4, (I), and C12H9BrO4, (II), are isomorphous and crystallize in the monoclinic space group P21/c. Both compounds present an anti conformation between the 3-carboxy and the lactone carbonyl groups. Both carbonyl groups are out of the plane defined by the remaining chromene atoms, by 8.37 (6) and 17.57 (6)° for (I), and by 9.07 (8) and 18.96 (18)° for (II), owing to their involvement in intermolecular interactions. In both compounds, layers of centrosymmetric hydrogen-bonded dimers are developed in the [\overline{5} \overline{2} 22] plane through C—H⋯O interactions, involving both carbonyl groups as acceptors. Two families of dimers stack through C=O⋯C=O, C=O⋯π and C—X⋯C=O (X = Cl and Br) dipolar interactions, as well as a C—H⋯π interaction, developing the three-dimensional structure along the c axis.

4,5-Dibromophthalimide forms two centrosymmetric dimers, one linked by C—H⋯O hydrogen bonds and one by N—H⋯O hydrogen bonds

Williamson, C. — 2007-03-15

In the title compound [also called 5,6-dibromoisoindole-1,3(2H)-dione], C8H3Br2NO2, there are two planar molecules in the asymmetric unit. They both form inversion dimers, one via N—H⋯O links and one via short near-linear C—H⋯O links. The dimers are then linked into chains by further N—H⋯O hydrogen bonds.

Dimorphism in 4,4,6,6-tetrachloro-2,2-(2,2-dimethylpropane-1,3-dioxy)cyclotriphosphazene and 6,6-dichloro-2,2:4,4-bis(2,2-dimethylpropane-1,3-dioxy)cyclotriphosphazene

Coles, S.J. — 2007-03-15

A second, polymorphic, form of the previously reported compound 4,4,6,6-tetrachloro-2,2-(2,2-dimethylpropane-1,3-dioxy)cyclotriphosphazene, C5H10Cl4N3O2P3, is now reported. The molecular structures of these two compounds are similar, aside from minor conformational differences. However, the compounds crystallize in two different space groups and exhibit quite different crystal structure assemblies. Additionally, 6,6-dichloro-2,2:4,4-bis(2,2-dimethylpropane-1,3-dioxy)cyclotriphosphazene, C10H20Cl2N3O4P3, is shown to exhibit two different conformational polymorphs when crystallized from different solvent mixtures. The α form crystallizes in the space group Pnma with the molecular structure lying on a mirror plane (symmetry code: x, −y + {1\over 2}, z), whilst the β form is in the space group C2/c with the molecular structure lying on a twofold axis (symmetry code: −x, y, −z + {3\over 2}). The difference between the two molecular structures is in the conformation of the spiro-ring substituents with respect to the phosphazene ring. The resulting crystal structures give rise to differing packing motifs.

4-Cyanobenzaldehyde isonicotinoylhydrazone monohydrate: a three-dimensional hydrogen-bonded framework structure

Souza, M.V.N. de — 2007-03-15

In the title compound, C14H10N4O·H2O, the molecular components are linked into a three-dimensional framework by three hydrogen bonds, one each of the O—H⋯O, O—H⋯N and N—H⋯O types, weakly augmented by two C—H⋯O hydrogen bonds.

6-(4-Fluorophenyl)-8-phenyl-2,3-dihydro-4H-imidazo[5,1-b][1,3]thiazin-4-one: an unusual [6–5] fused-ring system

Gallagher, J.F. — 2007-03-15

The title compound, C18H13FN2OS, is the first structural example of a [6–5] fused ring incorporating the 2,3-dihydro-4H-imidazo[5,1-b][1,3]thiazin-4-one molecular scaffold. The six-membered 2,3-dihydro-1,3-thiazin-4-one ring adopts an envelope conformation, with the S—CH2 C atom displaced by 0.761 (2) Å from the five-atom plane (all within 0.05 Å of the mean plane). The imidazole ring is planar. The phenyl ring is twisted from coplanarity with the imidazole ring by 23.84 (5)° and the 4-fluorophenyl ring is twisted by 53.36 (6)°, due to a close C(aryl)—H⋯O=C contact with the thiazin-4-one carbonyl O atom. The primary intermolecular interaction involves a CH2 group with the F atom [C⋯F = 3.256 (2) Å and C—H⋯F = 137°].

1-(6-Amino-1,3-benzodioxol-5-yl)-3-(4-pyridyl)prop-2-en-1-one crystallizes with Z′ = 2: hydrogen-bonded supramolecular substructures in one and two dimensions, each containing only one type of molecule

Cuervo, P. — 2007-02-15

The title compound, C15H12N2O3, crystallizes with Z′ = 2 in the space group P\overline{1} and the intramolecular dimensions show evidence for a polarized molecular–electronic structure. Each of the two independent types of molecule forms its own hydrogen-bonded supramolecular substructure, and these are entirely different from one another: one type of molecule forms a chain of edge-fused rings, while the other type forms sheets.

Five symmetrically substituted 2-aryl-3-benzyl-1,3-thiazolidin-4-ones: supramolecular structures in zero, one and two dimensions

Cunico, W. — 2007-02-15

There are no direction-specific interactions between the molecules of 3-(2-methoxybenzyl)-2-(2-methoxyphenyl)-1,3-thiazolidin-4-one, C18H19NO3S, (I); the molecules of 3-(4-nitrobenzyl)-2-(4-nitrophenyl)-1,3-thiazolidin-4-one, C16H13N3O5S, (II), are linked by four independent C—H⋯O hydrogen bonds into complex chains of fused rings. In 3-(4-methoxybenzyl)-2-(4-methoxyphenyl)-1,3-thiazolidin-4-one, (III), isomeric with (I), the molecules are linked into sheets by a combination of C—H⋯O and C—H⋯π(arene) hydrogen bonds, while in 3-(2-nitrobenzyl)-2-(2-nitrophenyl)-1,3-thiazolidin-4-one, (IV), isomeric with (II), the sheets are built from three independent C—H⋯O hydrogen bonds and one C—H⋯π(arene) hydrogen bond, and reinforced by an aromatic π–π stacking interaction. In 3-(2-fluorobenzyl)-2-(2-fluorophenyl)-1,3-thiazolidin-4-one, C16H13F2NOS, (V), where the 2-aryl ring exhibits orientational disorder, the molecules are linked into sheets by a combination of C—H⋯O and C—H⋯π(arene) hydrogen bonds, and the sheets are linked in pairs, forming bilayers, by an aromatic π–π stacking interaction.

Escitalopram oxalate: co-existence of oxalate dianions and oxalic acid molecules in the same crystal

Harrison, W.T.A. — 2007-02-15

The title compound {systematic name: (+)-(S)-3-[5-cyano-2-(4-fluorophenyl)-1,3-dihydroisobenzofuran-2yl]propanaminium oxalate oxalic acid 0.325-hydrate}, 2C20H22FN2O+·C2O42−·C2H2O4·0.325H2O, is a molecular salt of the N-protonated escitalopram cation. As well as charge-balancing oxalate dianions, neutral molecules of oxalic acid are present. The component species interact by way of N—H⋯O and short O—H⋯O hydrogen bonds, resulting in supramolecular chains.

2,3-Dimethoxybenzaldehyde isonicotinoylhydrazone chloroform monosolvate, and the mono- and dihydrates of 3,4,5-trimethoxybenzaldehyde isonicotinoylhydrazone: hydrogen-bonded supramolecular structures in one, two and three dimensions

Peralta, M.A. — 2007-01-15

In 2,3-dimethoxybenzaldehyde isonicotinoylhydrazone chloroform monosolvate, C15H15N3O3·CHCl3, the hydrazone molecules are linked by a combination of N—H⋯N and C—H⋯N hydrogen bonds into chains from which the chloroform molecules are pendent. 3,4,5-Trimethoxybenzaldehyde isonicotinoylhydrazone forms two stoichiometric hydrates. In the monohydrate, C16H17N3O4·H2O, the components are linked into sheets by a combination of O—H⋯O, O—H⋯N and N—H⋯N hydrogen bonds, and in the dihydrate, C16H17N3O4·2H2O, a combination of O—H⋯O, O—H⋯N and N—H⋯O hydrogen bonds links the components into a three-dimensional framework structure.

3-Nitrobenzaldehyde isonicotinoylhydrazone monohydrate redetermined at 120 K: sheets built from O—H⋯O, O—H⋯N, N—H⋯O and C—H⋯O hydrogen bonds

Wardell, S.M.S.V. — 2007-01-15

In the title compound, C13H10N4O3·H2O, the molecular components are linked into complex sheets by a combination of four types of hydrogen bonds.

1,4,8,11-Tetraazacyclotetradecane antimony(III) sulfide

Lees, R.J.E. — 2007-01-15

Poly[1,4,8,11-tetraazacyclotetradecane(2+) [hepta-μ-sulfido-trisulfidohexaantimony(III)]], {(C10H26N4)[Sb6S10]}n, consists of novel [Sb6S10]2− layers containing Sb2S2, Sb4S4 and Sb7S7 hetero-rings, which are separated by macrocyclic amine molecules. The macrocyclic amine molecules are disordered over two crystallographically distinct positions and are diprotonated in order to balance the charge of the anionic layers.

Hydrogen-bonded chains in 3-tert-butyl-5-[(4-methoxybenzyl)amino]-1-phenyl-1H-pyrazole and tetramolecular hydrogen-bonded aggregates in 5-[(benzotriazol-1-ylmethyl)(4-methoxybenzyl)amino]-3-tert-butyl-1-phenyl-1H-pyrazole

Abonía, R. — 2007-01-15

The molecules of 3-tert-butyl-5-[(4-methoxybenzyl)amino]-1-phenyl-1H-pyrazole, C21H25N3O, are linked into simple C(9) chains by a single C—H⋯N hydrogen bond. 5-[(Benzotriazol-1-ylmethyl)(4-methoxybenzyl)amino]-3-tert-butyl-1-phenyl-1H-pyrazole, C28H30N6O, crystallizes with Z′ = 2 in the space group P21/c. The molecules are weakly linked into centrosymmetric tetramolecular aggregates by a combination of C—H⋯N and C—H⋯O hydrogen bonds.

Three substituted 4-pyrazolylbenzoates: hydrogen-bonded supramolecular structures in one, two and three dimensions

Portilla, J. — 2007-01-15

The molecules of ethyl 4-(5-amino-3-methyl-1H-pyrazol-1-yl)benzoate, C13H15N3O2, are linked by two independent N—H⋯O hydrogen bonds into a chain of edge-fused and alternating R42(8) and R22(20) rings. A combination of N—H⋯N and N—H⋯O hydrogen bonds links the molecules of methyl 4-(5-amino-3-tert-butyl-1H-pyrazol-1-yl)benzoate, C15H19N3O2, into sheets of alternating R22(20) and R66(32) rings. In 4-(5-amino-3-methyl-1H-pyrazol-1-yl)benzoic acid monohydrate, C11H11N3O2·H2O, the molecular components are linked into a three-dimensional framework structure by a combination of five independent hydrogen bonds, two of O—H⋯N type and one each of O—H⋯O, N—H⋯O and N—H⋯N types.

Three ethyl 5-amino-1-aryl-1H-imidazole-4-carboxylates: hydrogen-bonded supramolecular structures in one, two and three dimensions

Costa, M.S. — 2007-01-15

The molecules of ethyl 5-amino-1-(4-cyanophenyl)-1H-imidazole-4-carboxylate, C13H12N4O2, are linked into a chain of alternating R22(10) and R44(34) rings by a combination of N—H⋯N and C—H⋯N hydrogen bonds. In ethyl 5-amino-1-(4-chlorophenyl)-1H-imidazole-4-carboxylate, C12H12ClN3O2, where the ethyl group is disordered over two sets of sites, a combination of N—H⋯O, N—H⋯N, C—H⋯N and C—H⋯π(arene) hydrogen bonds links the molecules into complex sheets. Two intermolecular hydrogen bonds, one each of N—H⋯N and C—H⋯O types, link the molecules of ethyl 5-amino-1-(2,6-difluorophenyl)-1H-imidazole-4-carboxylate, C12H11F2N3O2, into a continuous three-dimensional framework structure.

Two square-planar palladium(II) complexes with P,O-bidentate hybrid ligands

Elsegood, M.R.J. — 2007-01-15

In the two square-planar palladium(II) complexes chloro[(diphenylphosphinoamino)diphenylphosphine oxide]methylpalladium(II) dimethyl sulfoxide solvate, [Pd(CH3)Cl(C24H21NOP2)]·C2H6OS, (I), and chloro{[2-(diphenylphosphino)phenyl]diethoxymethane}methylpalladium(II), [Pd(CH3)Cl(C23H25O2P)], (II), a trans disposition of the diphenylphosphino and chloro groups is observed. The Pd atom in both complexes displays a distorted square-planar configuration formed by the four unique donor atoms (P, Cl, C and O). In compound (I), the five-membered Pd–P–N–P–O metallacycle is best described as having an envelope conformation, whereas in (II) the six-membered Pd–P–C–C–C–O metallacycle adopts a skewed boat conformation. Furthermore, within the P–N–P–O backbone in (I), the P—N distances are consistent with single-bond character [1.659 (3) and 1.692 (3) Å], whilst the P=O bond shows appreciable double-bond character [1.509 (2) Å].

The concomitant crystallization of two polymorphs of 1-deoxy-α-d-tagatose

Jones, N.A. — 2007-01-15

The crystalline form of 1-deoxy-d-tagatose, C6H12O5, is shown to be 1-deoxy-α-d-tagatopyranose; the absolute configuration is determined by use of d-lyxono-1,4-lactone as the starting material. The title compound crystallized as concomitant polymorphs from a mixture of ethyl actate and methanol. Although the melting points of the materials differ by 7 K, the molecular conformations are almost identical and, in both polymorphs, each molecule is subject to four O—H⋯O hydrogen bonds.

7-Amino-2-tert-butyl-5-methylpyrazolo[1,5-a]pyrimidine: a three-dimensional framework structure built from two N—H⋯N hydrogen bonds

Portilla, J. — 2007-01-15

The bond distances in the title compound, C11H16N4, provide evidence for peripheral delocalization of π electrons. The molecules are linked by two independent N—H⋯N hydrogen bonds into a three-dimensional framework structure.

Cocrystals composed of 4,4′-(fluorene-9,9-diyl)diphenol and 6-methyl-2H-pyridone

Lavy, T. — 2007-02-15

The crystal structures of two cocrystals composed of 4,4′-(fluorene-9,9-diyl)diphenol (C25H18O2) and 6-methyl-2H-pyridone (C6H7NO) are reported, namely 4,4′-(fluorene-9,9-diyl)diphenol–6-methyl-2H-pyridone (1/2), C25H18O2·2C6H7NO, (I), and 4,4′-(fluorene-9,9-diyl)diphenol–6-methyl-2H-pyridone–water (1/3/3), C25H18O2·3C6H7NO·3H2O, (II). In both cocrystals, the mutual orientation between two 6-methyl-2H-pyridone molecules in principle enables photodimerization, yet in both cases no photodimerization occurs. In cocrystal (I) this is probably due to poor orbital overlap, while in the case of cocrystal (II) it is suggested that the lack of reaction is due to the highly complex hydrogen-bonding network that exists in the structure.

Hydrogen-bonded chains of rings in methyl 4-[(5-methyl-1H-pyrazol-3-yl)amino]-3-nitrobenzoate and hydrogen-bonded sheets in methyl 1-(5-methyl-1H-pyrazol-3-yl)-1H-benzimidazole-5-carboxylate

Portilla, J. — 2007-01-15

Molecules of methyl 4-[(5-methyl-1H-pyrazol-3-yl)amino]-3-nitrobenzoate, C12H12N4O4, (I), exhibit a polarized (charge-separated) structure in the nitroaniline portion. The molecules are linked into chains of edge-fused R22(16) and R22(22) rings by a combination of N—H⋯O(carbonyl) and C—H⋯O(nitro) hydrogen bonds. Methyl 1-(5-methyl-1H-pyrazol-3-yl)-1H-benzimidazole-5-carboxylate, C13H12N4O2, (II), which is readily formed from (I) by reduction followed by ring formation, crystallizes with Z′ = 2 in the space group P\overline{1}. Each of the two independent molecular types is linked into sheets of R44(28) rings by a combination of N—H⋯N and C—H⋯O(carbonyl) hydrogen bonds.

Ammonium scandium tetrafluoride

Stephens, N.F. — 2006-12-15

The title compound, NH4ScF4, is an addition to the AMF4 family of layered perovskite-like structures. The structure consists of a two-dimensional array of corner-sharing ScF6 octahedra, which produces anionic sheets of stoichiometry [ScF4]− stacked along the c axis. The layers are separated by charge-balancing ammonium cations, which hydrogen bond to the apical F atoms of adjacent layers. This structure may be viewed as a `single-layer' fluoride analogue of the Dion–Jacobson family of oxides.

Dichloro(4,10-dimethyl-1,4,7,10-tetraazabicyclo[5.5.2]tetradecane)iron(III) hexafluorophosphate

McClain, J.M. II — 2006-11-15

The title compound, [FeCl2(C12H26N4)]PF6, is the first mononuclear Fe3+ complex of an ethylene cross-bridged tetraaza-macrocycle to be structurally characterized. Comparison with the mononuclear Fe2+ complex of the same ligand shows that the smaller Fe3+ ion is more fully encapsulated by the cavity of the bicyclic ligand. Comparison with the μ-oxo dinuclear complex of an unsubstituted ligand of the same size demonstrates that the methyl groups of 4,10-dimethyl-1,4,7,10-tetraazabicyclo[5.5.2]tetradecane prevent dimerization upon oxidation of the metal centre. Nax—Fe3+—Nax bond angles (ax is axial), and thus the degree of encapsulation by the ligand, are quite different between the mononuclear and dinuclear μ-oxo species, which is probably the consequence of steric considerations.

A second polymorph of [H3N(CH2)3NH3][V4O10]

Stephens, N.F. — 2006-11-15

The title compound, propane-1,3-diammonium tetravanadate, (C3H12N2)[V4O10], represents a second polymorph of composition β-[H3N(CH2)3NH3][V4O10]. It differs from the α polymorph [Riou & Ferey (1995). J. Solid State Chem. 120, 137–145] in the conformation of the propane-1,3-diammonium dication which, in the present example, lies on a twofold axis and adopts a syn–syn rather than a syn–anti conformation. The twofold symmetry of this conformation thus co-operates with the vanadium oxide framework to result in a higher symmetry for the resultant crystal, viz. C2/c versus P21/n. The overall unit-cell parameters for the two polymorphs are similar, and the inorganic layer within each is topologically identical, comprising edge-sharing VIVO5 square pyramids linked together via corner-sharing with VVO4 tetrahedra. A key difference between the two polymorphs is a `head-to-head' versus `head-to-tail' stacking of the vanadyl groups in adjacent layers.

Solvent-free synthesis and crystal structure of (Ph3PI)I5, the third member in the series Ph3P(I2)n (n = 1, 2 and 3)

Pritchard, R.G. — 2006-11-15

Red crystals of iodotriphenylphosphonium pentaiodide, C18H15IP+·I5−, appear on cooling the black melt formed by heating a mixture of the commonplace reagents triphenylphosphine and molecular iodine. The compound has the highest I:P ratio hitherto established for a crystalline iodophosphonium polyiodide and constitutes the third member of the series Ph3P(I2)n (n = 1, 2 and 3). All atoms occupy general positions in the triclinic space group P\overline{1}. Comparison of the bond lengths within the above series reveals a pattern of primary and secondary bonding that is highly reminiscent of the much studied polyiodides, I−2n+1, where one of the I2 moieties has been replaced by a P—I group.

3-Nitrophenylacetic acid: a three-dimensional hydrogen-bonded framework structure containing substructures in zero, one and two dimensions

Wardell, S.M.S.V. — 2006-11-15

In the title compound, C8H7NO4, the molecules are linked into a three-dimensional framework structure by a combination of O—H⋯O, C—H⋯O(carbonyl) and C—H⋯O(nitro) hydrogen bonds. Comparisons are made between the supramolecular structures of the three isomeric nitrophenylacetic acids.

Effects of d-orbital occupancy on the geometry of the trigonal–bipyramidal complexes [MIICl3(Hdabco)(dabco)]n, where M is Mn, Co, Ni or Cu and dabco is 1,4-diazabicyclo[2.2.2]octane

Pritchard, R.G. — 2006-11-15

Geometric data from (1-aza-4-azoniabicyclo[2.2.2]octane-κN1)(1,4-diazabicyclo[2.2.2]octane-κN1)trichloromanganese(II), [MnCl3(C6H13N2)(C6H12N2)] or [MnCl3(Hdabco)(dabco)] (dabco is 1,4-diazabicyclo[2.2.2]octane), and the cobalt(II) analogue, [CoCl3(C6H13N2)(C6H12N2)], have been combined with previously reported data for the Ni and Cu analogues to show that bond-length trends across the isotypal series are consistent with a high-spin trigonal–bipyramidal system. As each transition metal is positioned on a D3 site in the space group R32 (No. 155), two bond lengths fully define each trigonal–bipyramidal coordination geometry [Mn—Cl = 2.3903 (7) Å and Mn—N = 2.367 (2) Å, and Co—Cl = 2.3080 (8) Å and Co—N = 2.269 (3) Å].

Four substituted benzohydrazides: hydrogen-bonded structures in one, two and three dimensions

Wardell, S.M.S.V. — 2006-10-15

The molecules of 2,6-dichlorobenzohydrazide, C7H6Cl2N2O, are linked into simple chains by a single N—H⋯O hydrogen bond, while in the isomeric compound 2,4-dichlorobenzohydrazide, the molecules are linked by N—H⋯N and N—H⋯O hydrogen bonds into complex sheets comprising an inner polar layer sandwiched between two non-polar layers. In 4-amino-2-chlorobenzohydrazide monohydrate, C7H8ClN3O·H2O, the components are linked into a three-dimensional framework by a combination of O—H⋯O, O—H⋯N, N—H⋯N and N—H⋯O hydrogen bonds, and in 2-nitrobenzohydrazide, C7H7N3O3, a three-dimensional framework is formed by a combination of N—H⋯N and N—H⋯O hydrogen bonds

Comparison of copper imine and amine podates: geometric consequences of podand size and donor type

Coyle, J.L. — 2006-10-15

The imine podands tris[(2-nitrobenzylidene)aminoethyl]amine and tris[(2-nitrobenzylidene)aminopropyl]amine both stabilize copper(I), forming {tris[(2-nitrobenzylidene)aminoethyl]amine-κ4N}copper(I) perchlorate acetonitrile disolvate, [Cu(C27H27N7O6)]ClO4·2CH3CN, (II), and {tris[(2-nitrobenzylidene)aminopropyl]amine-κ4N}copper(I) perchlorate, [Cu(C30H33N7O6)]ClO4, (VI), respectively. The larger propyl-based ligand is a poorer fit for the CuI ion. The reduced amine podand tris[(2-nitrobenzyl)aminoethyl]amine binds CuII and the resulting compound, chloro{tris[(2-nitrobenzyl)aminoethyl]amine-κ4N}copper(II) chloride ethanol solvate, [Cu(C27H33N7O6)Cl]Cl·C2H5OH, (IV), shows both intra- and intermolecular hydrogen bonding, which gives rise to RRS or SSR conformations in the podand strands rather than the expected pseudo-threefold symmetry.

Chloro(diethylenetriamine)copper(II) chloride: a disordered quasi-one-dimensional structure

Pritchard, R.G. — 2006-10-15

The title structure, [CuCl(C4H13N3)]Cl, consists of alternating [CuCl(dien)]+ (dien is diethylenetriamine) and Cl− ions arranged in quasi-one-dimensional stacks along the crystallographic a axis and forming tetragonally elongated octahedral coordination shells around each Cu atom [equatorial Cu—Cl = 2.2552 (8) Å, and axial Cu—Cl = 2.831 (1) and 3.341 (1) Å]. Crystallographic mirror planes bisect each stack vertically through the Cu, Cl and central N atoms, and horizontally through the [CuCl(dien)]+ cation. The horizontal mirrors lead to each atom in the puckered [CuCl(dien)]+ cations being disordered over two crystallographically equivalent sites. Comparison of the title structure with its Br and I analogues shows a growing influence of hydrogen bonding relative to coordination bonds on traversing the series I < Br < Cl.

3-[5-(4-Bromophenyl)-1H-pyrazol-3-ylamino]-5,5-dimethylcyclohex-2-en-1-one–(Z)-3-(4-bromophenyl)-3-chloroacrylonitrile (2/1): a stoichiometric cocrystal of a reaction product with one of its early precursors

Cruz, S. — 2006-10-15

The title compound, 2C17H18BrN3O·C9H5BrClN, was crystallized from the reaction between 5,5-dimethylcyclohexane-1,3-dione, triethyl orthoformate and 5-amino-3-(4-bromophenyl)pyrazole, which had itself been prepared from the reaction between (Z)-3-(4-bromophenyl)-3-chloroacrylonitrile and hydrazine. The compound is a stoichiometric 2:1 cocrystal of the reaction product 3-[5-(4-bromophenyl)-1H-pyrazol-3-ylamino]-5,5-dimethylcyclohex-2-en-1-one and the early reactant (Z)-3-(4-bromophenyl)-3-chloroacrylonitrile. The two independent molecules of cyclohex-2-en-1-one are linked by N—H⋯N and N—H⋯O hydrogen bonds into complex bilayers and the molecules of acrylonitrile are trapped within large cavities in the substructure formed by the cyclohex-2-en-1-one molecules.

Hydrogen-bonded chains in racemic 2-benzyl-3-(2-bromophenyl)propiononitrile and hydrogen-bonded sheets in methyl 2-benzyl-2-cyano-3-phenylpropionate

Calderón, G. — 2006-09-15

The molecules of 2-benzyl-3-(2-bromophenyl)propiononitrile, C16H14BrN, are linked into chains by a single C—H⋯N hydrogen bond. The molecules of methyl 2-benzyl-2-cyano-3-phenylpropionate, C18H17NO2, are linked into sheets by a combination of C—H⋯O and C—H⋯π(arene) hydrogen bonds.

2,6-Dibromo-3,5-dimethylpyridine and 2,6-diiodo-3,5-dimethylpyridine

Pugh, D. — 2006-10-15

The title compounds 2,6-dibromo-3,5-dimethylpyridine, C7H7Br2N, (I), and 2,6-diiodo-3,5-dimethylpyridine, C7H7I2N, (II), constitute the first structurally characterized examples of 2,6-dihalo-3,5-dimethylpyridines. Compound (I) crystallizes as a racemic twin with two symmetry-independent molecules in the asymmetric unit, while (II) is non-planar with the pyridine ring slightly deformed into a saddle shape, and exhibits crystallographically imposed twofold symmetry. Both (I) and (II) exhibit aromatic face-to-face π-stacking in the solid state, although there are no other long-range interactions. In (I), alternate molecules are oriented at 90°, resulting in X-shaped columns, while in (II), molecules pack in a parallel fashion, leading to a zigzag array.

An unusual example of a linearly coordinated acetone ligand in a six-coordinate iron(II) complex

Kilner, C.A. — 2006-09-15

The title compound, acetonediaqua[2,6-bis(3-tert-butylpyrazol-1-yl)pyridine]iron(II) bis(tetrafluoroborate) acetone disolvate, [Fe(C19H25N5)(C3H6O)(H2O)2](BF4)2·2C3H6O, contains a C2-symmetric six-coordinate complex dication, with an acetone ligand in its equatorial plane that is linearly coordinated by symmetry (Fe—O=CMe2 = 180°). This is a consequence of close steric contacts between the coordinated carbonyl group and the two distal tert-butyl substituents on the tridentate ligand.

5-(2-Hydroxy-4,4-dimethyl-6-oxocyclohex-1-enyl)-3-methyl-2-(methylsulfanyl)-6-phenyl-7H-pyrrolo[2,3-d]pyrimidin-4(3H)-one monohydrate: complex sheets generated by multiple hydrogen bonds

Cruz, S. — 2006-09-15

In the title compound, C22H23N3O3S·H2O, the non-aromatic carbocyclic ring adopts a half-chair conformation. The molecules are linked into complex sheets by a combination of one N—H⋯O hydrogen bond and three O—H⋯O hydrogen bonds.

Three substituted (E)-3-aryl-2-(thienyl)acrylonitriles: isolated molecules, simple hydrogen-bonded chains and hydrogen-bonded sheets

Cobo, D. — 2006-09-15

The structure of (E)-2-(2-thienyl)-3-(3,4,5-trimethoxyphenyl)acrylonitrile, C16H15NO3S, contains no direction-specific intermolecular interactions. The molecules of (E)-3-(4-bromophenyl)-2-(2-thienyl)acrylonitrile, C13H8BrNS, exhibit orientational disorder of the thienyl fragment, and the molecules are linked into simple C(5) chains by a single C—H⋯N hydrogen bond. In (E)-3-phenyl-2-(3-thienyl)acrylonitrile, C13H9NS, the molecules are linked into sheets by a combination of one C—H⋯N hydrogen bond and one C—H⋯π(arene) hydrogen bond.

A hydrogen-bonded chain of rings in 7-amino-5-tert-butyl-2-methylpyrazolo[1,5-a]pyrimidine, and a hydrogen-bonded framework structure in 3,7-diamino-2,5-dimethylpyrazolo[1,5-a]pyrimidine monohydrate

Portilla, J. — 2006-08-15

In 7-amino-5-tert-butyl-2-methylpyrazolo[1,5-a]pyrimidine, C11H16N4, which crystallizes with Z′ = 2 in the space group P\overline{1}, the independent molecules are linked by four N—H⋯N hydrogen bonds into chains containing three types of ring. In 3,7-diamino-2,5-dimethylpyrazolo[1,5-a]pyrimidine monohydrate, C8H11N5·H2O, the molecular components are linked into a three-dimensional framework structure by a combination of O—H⋯N, N—H⋯N and N—H⋯O hydrogen bonds.

3-(5-Chloro-3-methyl-1-phenylpyrazol-4-yl)-1,5-diphenylpentane-1,5-dione: sheets built from C—H⋯O and C—H⋯π(arene) hydrogen bonds

Trilleras, J. — 2006-08-15

Molecules of the title compound, C27H23ClN2O2, are linked into sheets of alternating large and small rings by a combination of C—H⋯O and C—H⋯π(arene) hydrogen bonds.

3-(4-Methoxyphenyl)-7,7-dimethyl-1,6,7,8-tetrahydropyrazolo[3,4-b]quinolin-5-one: a chain of centrosymmetric rings built from N—H⋯N and C—H⋯π(arene) hydrogen bonds

Cruz, S. — 2006-08-15

In the title compound, C19H19N3O2, the non-aromatic carbocylic ring adopts an envelope conformation. The molecules are linked by a combination of N—H⋯N and C—H⋯π(arene) hydrogen bonds into a chain of centrosymmetric rings.

Poly[propane-1,3-diyldiammonium tetra-μ-selenito-trizinc dihydrate]

Ritchie, L.K. — 2006-09-15

The title compound, (C3H12N2)[Zn3(SeO3)4]·2H2O, is built up from organic cations, {[Zn3(SeO3)4]2−}n macroanionic sheets and water molecules. The inorganic component of the structure is notable for incorporating both octahedrally and tetrahedrally coordinated Zn atoms. A network of N—H⋯O and O—H⋯O hydrogen bonds helps to establish the layered structure. The six-coordinate Zn atom has site symmetry \overline{1}, and one C and the two water O atoms have site symmetry m.

A polymeric solvent-free variant of a hydridomagnesium inverse crown

Graham, D.V. — 2006-08-15

A solvent-free agostically propagated polymeric variant of a previously reported hydride-containing inverse crown molecule has been prepared, namely tetra-μ2-diisopropylamido-di-μ2-hydrido-dimagnesium(II)disodium(I), [Mg2Na2H2(C6H14N)4]. The asymmetric unit contains two crystallographically independent centrosymmetric molecules, each existing as a cationic eight-membered ring, with alternating metal and N atoms, which acts as a host towards two hydride anions. The metal amide rings are linked via Na⋯C agostic interactions to produce one-dimensional polymeric chains propagating along the crystallographic b direction.

Poly[(2,2′-bipyridine-κ2N,N′)(μ2-dihydrogen phosphato-κ2O:O′)(μ2-hydrogen phosphato-κ2O:O′)aluminium(III)], Al(2,2′-bipy)(HPO4)(H2PO4), a layered inorganic–organic hybrid material

Chippindale, A.M. — 2006-08-15

The title compound, [Al(HPO4)(H2PO4)(C10H8N2)]n, consists of AlO4N2 octahedra vertex-linked to H2PO4 and HPO4 tetrahedra to form layers based on a (4,12)-net. The layers stack in an AAA fashion, held in place by π–π interactions between 2,2′-bipyridine molecules coordinated to Al atoms in adjacent layers.

Tetrathiafulvalene revisited

Batsanov, A.S. — 2006-08-15

Monoclinic (α) tetrathiafulvalene [systematic name: 2-(1,3-dithiol-2-ylidene)-1,3-dithiole], C6H4S4, undergoes a reversible second-order phase transition at ca 190 K through a displacive modulation with doubling of the a parameter. The low-temperature phase (γ) contains two crystallographically non-equivalent (but centrosymmetric) molecules of very similar geometry.

2,4-Dimethylbenzaldehyde isonicotinoylhydrazone trihydrate: a three-dimensional hydrogen-bonded framework structure

Low, J.N. — 2006-07-15

In the title compound, C15H15N3O·3H2O, two of the three water molecules exhibit disorder. The molecular components are linked into a three-dimensional framework by a combination of N—H⋯O, O—H⋯N and O—H⋯O hydrogen bonds.

1-(Isopropylideneamino)guanidinium 2-nitrobenzoate: formation of corrugated sheets from R22(8) and R64(16) rings

Skakle, J.M.S. — 2006-08-15

In the title compound, C4H11N4+·C7H4NO4−, the guanidinium cation acts as a strong hydrogen-bonding donor via the guanidine NH2 and NH groups, with the carboxy groups of the nitrobenzoate group acting as the acceptors. These hydrogen bonds lead to fused R22(8) and R64(16) rings, which form corrugated sheets perpendicular to [010].

N-(2-Hydroxy-3-iodo-5-nitrobenzylidene)-3-nitroaniline: conformational isomers linked into complex sheets by five C—H⋯O hydrogen bonds and a two-centre iodo–nitro interaction

Low, J.N. — 2006-07-15

The title compound, C13H8IN3O5, crystallizes with Z′ = 2 in the space group P21/n. The two independent molecules, which are both almost planar, are conformational isomers. The molecules are linked into complex sheets by a combination of five independent C—H⋯O hydrogen bonds and an almost linear two-centre iodo–nitro interaction.

5-Fluorouracil and thymine form a crystalline solid solution

Barnett, S.A. — 2006-07-15

The crystal structure of a 5-fluorouracil–thymine [5-fluoropyrimidine-2,4(1H,3H)-dione–5-methylpyrimidine-2,4(1H,3H)-dione, C4H3FN2O2·C5H6N2O2] solid solution has been determined. Both of the crystallographically independent sites can accommodate either 5-fluorouracil or thymine molecules, leading to occupational disorder [C5−xH6–3xFxN2O2·C5−yH6−3xFyN2O2, with x = 0.52 and y = 0.7 for determination (I), x = 0.55 and y = 0.69 for (II), and x = 0.67 and y = 0.76 for (III)]. The 5-fluorouracil–thymine ratio in the crystal structure is influenced by the 5-fluorouracil–thymine ratio in the crystallization solution, though it does not exactly mirror it. The crystal structure comprises interpenetrating hydrogen-bonded nets, containing four independent hydrogen bonds.

4-Iodo-N,N-bis(2-nitrophenylsulfonyl)aniline: a three-dimensional framework structure built from six independent C—H⋯O hydrogen bonds

Low, J.N. — 2006-07-15

In the title compound [systematic name: 4-iodophenylimino bis(2-nitrobenzenesulfinate)], C18H12IN3O8S2, where the molecules do not exhibit even approximate local symmetry, the molecules are linked into a complex three-dimensional structure by six independent C—H⋯O hydrogen bonds, which utilize O atoms in nitro and sulfonyl groups as the acceptors.

Hydrated forms of N-[(3R)-3-(4-methyl-3,5-dioxo-1,2,4-triazolidin-1-yl)-2-methylenebutanoyl]-(1S,2R)-bornane-10,2-sultam and its enantiomerPart of this work was presented as a poster at the 13th International Conference on Organic Synthesis (ICOS-13), Warsaw, Poland, July 1–5, 2000; Y. Elemes: Highly Diastereoselective Ene Reactions with the Aid of a Chiral Auxiliary, p. 265.

Elemes, Y. — 2006-08-15

Triazolidinediones react with each enantiomeric bornanesultam derivative of tiglic acid to produce the appropriate ene adduct in high yield and with excellent regioselectivity and diastereoselectivity. The optically pure products, viz. N-[(3R)-3-(4-methyl-3,5-dioxo-1,2,4-triazolidin-1-yl)-2-methylenebutanoyl]-(1S,2R)-bornane-10,2-sultam 0.15-hydrate, C18H26N4O5S·0.15H2O, and its enantiomer N-[(3S)-3-(4-methyl-3,5-dioxo-1,2,4-triazolidin-1-yl)-2-methylenebutanoyl]-(1R,2S)-bornane-10,2-sultam 0.35-hydrate, C18H26N4O5S·0.35H2O, have been characterized by spectroscopy and single-crystal X-ray analysis. Their structures are the result of Cβ-re attack of the enophile on the double bond of the alkene.

{Bis(3,5-Di-tert-butyl-2-oxidobenzyl)[2-(N,N-dimethylamino)ethyl]amine-κ4N,N′,O,O′}zinc(II) and {bis(3-tert-butyl-5-methyl-2-oxidobenzyl)[2-(N,N-dimethylamino)ethyl]amine-κ4N,N′,O,O′}(tetrahdyrofuran)zinc(II)

Howard, R.H. — 2006-07-15

The title zinc(II) complexes, [Zn(C34H54N2O2)], (II), and [Zn(C28H42N2O2)(C4H8O)], (III), were obtained as monomeric 1:1 complexes, in contrast with the calcium complexes supported by the same ligand class. Complex (II) crystallizes with two independent molecules in the asymmetric unit, which have similar geometric parameters. The donor atoms in (II) form a distorted trigonal–pyramidal arrangement around the zinc centre. Complex (III) contains a coordinated tetrahydrofuran molecule, resulting in a five-coordinate trigonal–bipyramidal arrangement around the Zn atom. The electron density provided by the coordination of this tetrahydrofuran molecule elongates the Zn—O and Zn—N bonds by approximately 0.07 and 0.10 Å, respectively, in comparison with (II). Neither (II) nor (III) is active as an ∊-caprolactone polymerization catalyst. The data presented here demonstrate that Zn may bind both an ONNO ligand and an additional oxygen-based ligand. The lack of activity is thus not due to steric hinderance at the metal atom.

Three substituted (Z)-5-benzylidene-2-thioxothiazolidin-4-ones: hydrogen-bonded dimers that can be effectively isolated or linked into chains either by aromatic π–π stacking interactions or by dipolar carbonyl–carbonyl interactions

Delgado, P. — 2006-07-15

In each of the isomeric compounds (Z)-5-(2-fluorobenzylidene)-2-thioxothiazolidin-4-one, C10H6FNOS2, (I), and (Z)-5-(4-fluorobenzylidene)-2-thioxothiazolidin-4-one, C10H6FNOS2, (II), there is a very wide C—C—C angle (ca 130°) at the methine C atom linking the two rings. In each isomer, paired N—H⋯O hydrogen bonds link the molecules into centrosymmetric R22(8) dimers; the hydrogen-bonded dimers are linked into chains by an aromatic π–π stacking interaction in isomer (I) and by an antiparallel dipolar carbonyl–carbonyl interaction in isomer (II). (Z)-5-(3,4,5-Trimethoxybenzylidene)-2-thioxothiazolidin-4-one, C13H13NO4S2, (III), which crystallizes with Z′ = 2 in the space group P\overline{1}, shows the same very wide angle at the bridging methine C atom; the two independent molecules are linked into an isolated dimer having no crystallographic symmetry.

Four 2-aryl-8,8-dimethyl-6,7,8,9-tetrahydropyrazolo[2,3-a]quinazolin-6-ones: isolated molecules, hydrogen-bonded dimers, and π-stacked chains of hydrogen-bonded dimers

Cruz, S. — 2006-06-15

In each of the three compounds 2-(4-chlorophenyl)-5,8,8-trimethyl-6,7,8,9-tetrahydropyrazolo[2,3-a]quinazolin-6-one, C19H18ClN3O, (I), 2-(4-methoxyphenyl)-5,8,8-trimethyl-6,7,8,9-tetrahydropyrazolo[2,3-a]quinazolin-6-one, C20H21N3O2, (II), and 8,8-dimethyl-2-(4-methylphenyl)-6,7,8,9-tetrahydropyrazolo[2,3-a]quinazolin-6-one monohydrate, C19H19N3O·H2O, (IV), the non-aromatic carbocyclic ring adopts a half-chair conformation, while in 2-(4-chlorophenyl)-8,8-dimethyl-5-phenyl-6,7,8,9-tetrahydropyrazolo[2,3-a]quinazolin-6-one, C24H20ClN3O, (III), the corresponding ring adopts a conformation intermediate between the envelope and screw–boat forms. The structure of (I) consists of isolated molecules, while that of (II) contains dimers formed by C—H⋯O hydrogen bonds. In (III), dimers formed by C—H⋯O hydrogen bonds are linked into chains by means of an aromatic π–π stacking interaction, while in the monohydrate, (IV), the heterocyclic molecules and the water molecules are linked by O—H⋯O and O—H⋯N hydrogen bonds to form centrosymmetric four-component aggregates.

2-Bromo-1,3-bis(bromomethyl)benzene, with Z′ = 1.5: whole-molecule disorder of one of the two independent molecules

Kirsop, P. — 2006-07-15

The title compound, C8H7Br3, possesses normal geometrical parameters. There are two independent molecules; one shows whole-molecule disorder with respect to an inversion-symmetry-generated partner, while the other is undisordered. This results in the unusual situation of Z′ = 1.5 and Z = 6 for a monoclinic crystal system. The undisordered molecule interacts with its neighbours by way of π–π stacking.

1,2-Bis(diphenylphosphino)benzene and two related mono-methiodides, [o-C6H4(PR2)(PR2Me)]I (R = Ph or Me)

Levason, W. — 2006-07-15

The structures of the compounds 1,2-bis(diphenylphosphino)benzene, C30H24P2, [2-(diphenylphosphino)phenyl]methyldiphenylphosphonium iodide, C31H27P2+·I−, and [2-(dimethylphosphino)phenyl]trimethylphosphonium iodide, C11H19P2+·I−, show that quaternization only occurs at one P centre and results in significantly shorter P—C bonds and larger C—P—C angles, consistent with the formal oxidation from PIII to PV.

Hydrogen-bonded chains of rings linked by iodo–carbonyl interactions in 5-iodoisatin and hydrogen-bonded sheets in 7-trifluoromethylisatin

Garden, S.J. — 2006-06-15

In 5-iodoisatin (5-iodo-1H-indole-2,3-dione), C8H4INO2, the molecules are linked into chains of rings by N—H⋯O and C—H⋯O hydrogen bonds, and these chains are linked into sheets by iodo–carbonyl interactions. In 7-trifluoromethylisatin (7-trifluoromethyl-1H-indole-2,3-dione), C9H4F3NO2, the molecules are linked into sheets of centrosymmetric R22(8) and R66(34) rings by N—H⋯O and C—H⋯O hydrogen bonds.

(1Z,2Z)-1,2-Bis(3-methyl-2,3-dihydro-1,3-benzothiazol-2-ylidene)hydrazine

Nakano, T. — 2006-06-15

The title compound, C16H14N4S2, crystallizes in symmetry group C2. The molecule is planar with C2h symmetry, with the inversion centre at the mid-point of the hydrazine N—N bond, and it has an N—N s-trans conformation and a Z,Z configuration. The particular crystal examined was a racemic twin, as suggested by the Flack parameter of 0.41 (2) [Flack (1983). Acta Cryst. A39, 876–881].

Arene–perfluoroarene interactions in crystal engineering. XV. Ferrocene–decafluorobiphenyl (1/1)For Part XIV, see Collings et al. (2006).

Batsanov, A.S. — 2006-06-15

The title crystal, [Fe(C5H5)2]·C12F10, comprises infinite chains of alternating component molecules, linked through face-to-face contacts of nearly parallel cyclopentadienyl and pentafluorophenyl rings. The decafluorobiphenyl molecule has a crystallographic twofold axis and the Fe atom of the ferrocene molecule is on a crystallographic inversion centre, with both cyclopentadienyl rings disordered.

Sheets built from C—H⋯O and C—H⋯π(arene) hydrogen bonds in (2RS,6SR)-N-diphenylacetyl-2,6-diphenylpiperidin-4-one and (2RS,3SR,5RS,6SR)-3,5-dimethyl-N-phenylacetyl-2,6-diphenylpiperidin-4-one

Thanikasalam, K. — 2006-06-15

In (2RS,6SR)-N-diphenylacetyl-2,6-diphenylpiperidin-4-one, C31H27NO2, (I), the piperidinone ring adopts an almost ideal twist–boat conformation, and the molecules are linked into sheets by a combination of one C—H⋯O hydrogen bond and one C—H⋯π(arene) hydrogen bond. (2RS,3SR,5RS,6SR)-3,5-Dimethyl-2,6-diphenyl-N-phenylacetylpiperidin-4-one, C27H27NO2, (II), crystallizes with Z′ = 2 in the space group P\overline{1}; the piperidinone rings adopt an almost ideal boat conformation in one of the molecules and a conformation between boat and twist–boat in the other. The molecules of (II) are linked into sheets by a combination of five C—H⋯O hydrogen bonds and one C—H⋯π(arene) hydrogen bond.

Formation of ladders from R44(8) and R66(12) rings in 8-hydroxyquinolinium chloride monohydrate: comparisons with the supramolecular arrangements in related salts

Skakle, J.M.S. — 2006-06-15

Molecules of the title compound, C9H8NO+·Cl−·H2O, are linked into two rings by strong hydrogen bonding via the free water molecules and the Cl− anions. The two hydrogen-bonded rings are joined to give a corrugated chain along [001]. Comparisons with other 8-hydroxyquinoline-based salts are also presented, highlighting similar ring structures in a 1:1 salt with Kemp's triacid (r-1,c-3,c-5-trimethylcyclohexane-1,3,5-tricarboxylic acid) and in 8-hydroxy-1-methylquinolinium chloride monohydrate.

2,4-Dinitrophenylhydrazine, redetermined at 120 K: a three-dimensional framework built from N—H⋯O, N—H⋯(O)2, N—H⋯π(arene) and C—H⋯O hydrogen bonds

Wardell, J.L. — 2006-06-15

In the title compound, C6H6N4O4, the bond distances indicate significant bond fixation, consistent with charge-separated polar forms. The molecules are almost planar and there is an intramolecular N—H⋯O hydrogen bond. The molecules are linked into a complex three-dimensional framework structure by a combination of N—H⋯O, N—H⋯(O)2, N—H⋯π(arene) and C—H⋯O hydrogen bonds.

2-(4-Chloroanilino)- and 2-(4-methoxyanilino)-1,2-diphenylethanone

Batsanov, A.S. — 2006-05-15

The title compounds, C20H16ClNO and C21H19NO2, adopt syn orientations of the C=O and N—H bonds but, like their analogues, form no strong intermolecular hydrogen bonds.

PbZn1/3Nb2/3O3 at 4.2 and 295 K

Kisi, E.H. — 2006-06-15

The structure of the relaxor ferroelectric lead zinc niobium trioxide, Pb(Zn1/3Nb2/3)O3, known as PZN, was determined at 4.2 and 295 K from very high resolution neutron powder diffraction data. The material is known for its extraordinary piezoelectric properties which are closely linked to the structure. Pseudo-cubic lattice parameters have led to considerable controversy over the symmetry of the structure, which was found to be rhombohedral in the space group R3m at both temperatures. Atomic coordinates have been determined for the first time. They show that, whereas the deviation of the rhombohedral angle from 90° approaches zero at 295 K, the atomic coordinates do not approach typical cubic positions and hence the polarization remains high.

(Nitrato-κ2O,O′)bis(triethanolamine-κ4N,O,O′,O′′)lanthanum(III) dinitrate

Fowkes, A. — 2006-06-15

The title compound, [La(NO3)(C6H15NO3)2](NO3)2, contains a network of [La(NO3)(C6H15NO3)2]2+ cations and nitrate counter-ions. The crystal packing is influenced by cation-to-anion O—H⋯O hydrogen bonds, resulting in a structure with one-dimensional character. The ten-coordinate La atom and a nitrate anion have site symmetry 2. The fact that triethanolamine can bind to such diverse cations as Li+ and La3+ militates against possible applications that require selective binding of ligand to metal.

Conformations of three heterocyclic perhydropyrrolobenzofurans and polymeric assembly via co-operative intermolecular C—H⋯O hydrogen bonds

Yathirajan, H.S. — 2006-05-15

In 1-cyclohexyl-6,6,8a-trimethyl-3a,6,7,8a-tetrahydro-1H-1-benzofuro[2,3-b]pyrrole-2,4(3H,5H)-dione, C19H27NO3, (I), and the isomorphous compounds 6,6,8a-trimethyl-1-phenyl-3a,6,7,8a-tetrahydro-1H-1-benzofuro[2,3-b]pyrrole-2,4(3H,5H)-dione, C19H21NO3, (II), and 6,6,8a-trimethyl-1-(3-pyridyl)-3a,6,7,8a-tetrahydro-1H-1-benzofuro[2,3-b]pyrrole-2,4(3H,5H)-dione, C18H20N2O3, (III), the tetrahydrobenzo–dihydrofuro–pyrrolidine ring systems are folded at the cis junction of the five-membered rings, giving rise to a non-planar shape of the tricyclic cores. The dihydrofuran and pyrrolidine rings in (I) are puckered and adopt an envelope conformation. The cyclohexene rings adopt a half-chair conformation in all the molecules, while the substituent N-cyclohexyl ring in (I) assumes a chair form. Short intramolecular C—H⋯O contacts form S(5) and S(6) motifs. The isomorphous compounds (II) and (III) are effectively isostructural, and aggregate into chains via intermolecular C—H⋯O hydrogen bonds.

An orthorhombic polymorph of 10,11-dihydrocarbamazepine

Harrison, W.T.A. — 2006-05-15

The title compound (systematic name: 10,11-dihydro-5H-dibenz[b,f]azepine-5-carboxamide), C15H14N2O, is shown to crystallize as an orthorhombic polymorph to complement the known monoclinic form. The molecular conformations of both forms are very similar, involving a bent conformation for the seven-membered azepine ring and an overall `butterfly' shape. The molecules assemble into chains by way of N—H⋯O bonds and N—H⋯π interactions in both crystal modifications. The two polymorphs appear to form due to different van der Waals interactions between the layer-like sheets of molecules.

N-(2-Methoxy-6-oxo-1,6-dihydropyrimidin-4-yl)formamide: hydrogen-bonded sheets of centrosymmetric R22(8) and R64(28) rings

Torre, J.M. de la — 2006-05-15

Molecules of the title compound, C6H7N3O3, are linked into sheets of centrosymmetric R22(8) and R64(28) rings by two nearly linear N—H⋯O hydrogen bonds [H⋯O = 1.91 and 1.98 Å, N⋯O = 2.786 (3) and 2.862 (3) Å, and N—H⋯O = 175 and 177°].

A three-dimensional framework of π-stacked hydrogen-bonded chains in benzyl 4-chloro-3-nitrobenzoate, and chains of hydrogen-bonded rings in benzyl 4-nitrobenzoate, redetermined at 120 K

Souza, M.V.N. de — 2006-05-15

Benzyl 4-chloro-3-nitrobenzoate, C14H10ClNO4, crystallizes with Z′ = 2 in the space group P\overline{1}. The molecules are linked by three independent C—H⋯O hydrogen bonds into chains of edge-fused R44(26) and R44(34) rings, and these chains are linked into a three-dimensional framework structure by aromatic π–π stacking interactions. In benzyl 4-nitrobenzoate, C14H11NO4, the molecules are linked by two independent C—H⋯O hydrogen bonds into chains containing two types of R22(10) ring.

Hydrogen-bonded sheets in racemic cis-(2,2′-bipyridyl-κ2N,N′)oxo(pentane-2,4-dionato-κ2O,O′)(thiocyanato-κN)vanadium(IV)

Kavitha, S.J. — 2006-05-15

The title compound, [V(C5H7O2)(NCS)O(C10H8N2)], crystallizes with Z′ = 2 in the space group Pbca. The molecules are linked into sheets by a combination of four C—H⋯O hydrogen bonds and one C—H⋯N hydrogen bond. The four C—H⋯O hydrogen bonds generate chains of rings, where each chain contains just a single enantiomer of each of the two independent molecules, while the C—H⋯N hydrogen bond generates a chain containing both enantiomers of just one of the independent molecules.

Poly[piperazinium(2+) [hexa-μ-hydrogen phosphito-μ-piperazine-pentazinc(II)]]

Harrison, W.T.A. — 2006-04-15

The title compound, {(C4H12N2)[Zn5(HPO3)6(C4H10N2)]}n contains ZnO4, ZnO3N and HPO3 polyhedral building units linked by Zn—O—P bridges (mean Zn—O—P = 133.6°). The organic species exists in two forms, i.e. as neutral molecules that bond directly to zinc as ligands via both N atoms and as diprotonated cations that interact with the framework by way of N—H⋯O hydrogen bonds. Both organic components lie across centres of inversion.

Oxalate complexes of the (η6-p-cymene)ruthenium(II) fragment: μ-oxalato-κ2O1,O2:κ2O1′,O2′-bis[(η6-p-cymene)(triphenylphosphine-κP)ruthenium(II)] bis(tetrafluoroborate) and (η6-p-cymene)(oxalato-κ2O,O′)(pyridine-3,5-dicarboxylic acid-κN)ruthenium(II)

Dale, S.H. — 2006-04-15

The crystal structure of dimeric μ-oxalato-bis[(η6-p-cymene)(triphenylphosphine)ruthenium(II)] bis(tetrafluoroborate), [Ru2(C2O4)(C10H14)2(C18H15P)2](BF4)2, has the cation lying on an inversion centre. The complex demonstrates the trans bond-weakening influence, with the longest Ru—C(η6-p-cymene) bonds in the complex lying trans to the phosphine group. The related mononuclear species (η6-p-cymene)(oxalato)(pyridine-3,5-dicarboxylic acid)ruthenium(II), [Ru(C2O4)(C10H14)(C7H5NO4)], crystallizes as hydrogen-bonded tapes linked through O—H⋯O hydrogen bonds.

Hydrogen-bonded framework structures in 4-[(4-chloro-3-nitrobenzoyl)hydrazinocarbonyl]pyridinium chloride and N-3,5-dinitrobenzoyl-N′-isonicotinoylhydrazine

Vasconcelos, T.R.A. — 2006-04-15

In 4-[(4-chloro-3-nitrobenzoyl)hydrazinocarbonyl]pyridinium chloride, C13H10ClN4O4+·Cl−, the component ions are linked into a three-dimensional framework structure by a combination of three N—H⋯Cl and five C—H⋯O hydrogen bonds. In N-3,5-dinitrobenzoyl-N′-isonicotinoylhydrazine, C13H9N5O6, the molecules are linked into a three-dimensional framework structure by one N—H⋯O and three C—H⋯O hydrogen bonds, augmented by an aromatic π–π stacking interaction.

(–)-(5S,8S,9R,10S,13R,14R)-15,16-Dideoxy-16,17-epoxy-16-oxospongian-15-yl acetate

Blake, A.J. — 2006-04-15

The title compound (aplyroseol-14), C22H34O4, exhibits a lactone-based structure that is novel for spongian-type diterpenoids. The structure, which features a six-membered lactone ring, was proposed by Arnó, González & Zaragozá [J. Org. Chem. (2003), 68, 1242–1251] on the basis of spectroscopic data and chemical correlations. This assignment has been confirmed, and it is shown that the molecule contains a trans–anti–trans 6/6/6 tricyclic hydrocarbon system and that the acetoxymethyl group lies in an equatorial position. Pairs of near-linear C—H⋯O interactions link molecules into extended chains.

(3-Hydroxy-2-pyridylmethyl)dimethylammonium dihydrogenphosphate

Demir, S. — 2006-04-15

The title compound, C8H13N2O+·H2PO4−, is an ionic salt. The organic species is protonated at the N atom of the dimethylaminomethyl group. The dihydrogenphosphate moieties are connected into infinite chains by way of O—H⋯O links. The H2PO4− group also makes an O—H⋯N hydrogen bond to the pyridine N atom of the organic species. The organic cations crosslink the phosphate chains into a three-dimensional network by way of strong N—H⋯O and O—H⋯O interactions.

7-Amino-2,5-dimethylpyrazolo[1,5-a]pyrimidine hemihydrate redetermined at 120 K: a three-dimensional hydrogen-bonded framework

Portilla, J. — 2006-04-15

In the title compound, C8H10N4·0.5H2O, where the water molecules lie on twofold rotation axes in the space group C2, the components are linked by three hydrogen bonds, one each of O—H⋯N, N—H⋯N and N—H⋯O types, into a complex three-dimensional framework structure.

Simple hydrogen-bonded chains in 2,2′-bipyridinium thiocyanate, hydrogen-bonded chains of rings in 2,2′-bipyridinium picrate and hydrogen-bonded sheets in 2,2′-bipyridinium hydrogensulfate

Kavitha, S.J. — 2006-04-15

In 2,2′-bipyridinium thiocyanate, C10H9N2+·NCS−, the cations are disordered over two sets of sites with occupancies of 0.845 (2) and 0.155 (2). The ions are linked into simple chains by a combination of N—H⋯N and C—H⋯N hydrogen bonds, regardless of the orientation of the cation. In 2,2′-bipyridinium picrate, C10H9N2+·C6H2N3O7−, the bond distances in the anion indicate a markedly non-classical electronic structure; the component ions are linked by a combination of six independent hydrogen bonds, viz. one of N—H⋯O type and five of C—H⋯O type, into a complex chain containing five distinct types of ring. The ions in 2,2′-bipyridinium hydrogensulfate, C10H9N2+·HSO4−, are linked by a combination of five hydrogen bonds, viz. one each of O—H⋯O and N—H⋯O types, and three of C—H⋯O type, into complex sheets built from two one-dimensional substructures, each in the form of a complex chain of rings.

N,N′-Bis(2-chloronicotinoyl)-N-(3-nitrophenyl)hydrazine monohydrate: complex sheets built from O—H⋯N, N—H⋯O and C—H⋯O hydrogen bonds

Wardell, S.M.S.V. — 2006-04-15

In the title compound, C18H11Cl2N5O4·H2O, the two components are linked into complex sheets by a combination of five independent hydrogen bonds, viz. one of N—H⋯O type and two each of O—H⋯N and C—H⋯O types.

Neutron diffraction studies of the 1:1 and 2:1 cocrystals of benzene-1,2,4,5-tetracarboxylic acid and 4,4′-bipyridine

Cowan, J.A. — 2006-04-15

The 1:1 and 2:1 cocrystals of benzene-1,2,4,5-tetracarboxylic acid (BTA) and 4,4′-bipyridine (BPY) have been studied using neutron diffraction at 215 and 20 K, respectively. BTA and BPY crystallize in a 1:1 ratio with 1.8 molecules of water, viz. 4,4′-bipyridinium 2,5-dicarboxybenzene-1,4-dicarboxylate 1.8-hydrate, C10H12N22+·C10H4O82−·1.8H2O, (I), in the space group P\overline{1}, with both BTA and BPY lying on inversion centres. BTA and BPY crystallize in a 2:1 ratio, viz. 4,4′-bipyridinium bis(2,4,5-tricarboxybenzoate), C10H12N22+·2C10H5O8−, (II), in the space group Cc. The crystal structure of the 1:1 cocrystal contains one short N—H⋯O hydrogen bond [N⋯O = 2.6047 (19) Å] and one intramolecular O—H⋯O hydrogen bond [O⋯O = 2.423 (3) Å]. The crystal structure of the 2:1 cocrystal contains two N—H⋯O hydrogen bonds [N⋯O = 2.639 (3) and 2.674 (2) Å], and two intramolecular [O⋯O = 2.404 (3) and 2.420 (3) Å] and four strong intermolecular O—H⋯O hydrogen bonds [O⋯O = 2.613 (3), 2.718 (3), 2.628 (3) and 2.739 (3) Å].

4,5,6-Triamino-2-(methylsulfanyl)pyrimidine: π-stacked hydrogen-bonded sheets of R22(8), R22(10) and R66(32) rings

Cobo, J. — 2006-03-15

In the title compound, C5H9N5S, the three independent C—NH2 units are all somewhat pyramidal. The molecules are linked by a combination of one N—H⋯S and two N—H⋯N hydrogen bonds into sheets containing three types of ring motif, viz. R22(8), R22(10) and R66(32), all of them centrosymmetric. Adjacent sheets are linked by a single π–π stacking interaction.

Racemic cis-methoxobis(2-methyl-3-oxo-4H-pyran-4-olato)oxovanadium(V) redetermined at 120 K: hydrogen-bonded ribbons containing R22(7), R22(14) and R44(18) rings

Kavitha, S.J. — 2006-03-15

In the title compound, [V(CH3O)(C6H5O3)2O], the V—O bond lengths to the oxo and methoxo ligands are 1.593 (3) and 1.768 (3) Å, respectively, at 120 K; the V—O bond lengths trans to these two ligands are 2.246 (3) and 2.116 (3) Å. Molecules are linked by three C—H⋯O hydrogen bonds into complex ribbons containing three types of ring.

Isolated molecules in 2-ethylsulfanyl-7-methyl-4-(4-methylphenyl)pyrazolo[1,5-a][1,3,5]triazine and hydrogen-bonded sheets of R22(10), R22(16), R44(22) and R44(24) rings in 2-ethylsulfanyl-7-methyl-4-(4-nitrophenyl)pyrazolo[1,5-a][1,3,5]triazine

Insuasty, H. — 2006-03-15

In each of 2-ethylsulfanyl-7-methyl-4-(4-methylphenyl)pyrazolo[1,5-a][1,3,5]triazine, C15H16N4S, (I), and 2-ethylsulfanyl-7-methyl-4-(4-nitrophenyl)pyrazolo[1,5-a][1,3,5]triazine, C14H13N5O2S, (II), there is significant bond fixation in the heterocyclic component. While there are no direction-specific intermolecular interactions in the structure of (I), the molecules of (II) are linked by a combination of C—H⋯O and C—H⋯S hydrogen bonds into sheets containing four types of ring, all centrosymmetric.

2,4-Difluorobenzaldehyde benzoylhydrazone and 2,4-dichlorobenzaldehyde benzoylhydrazone are isostructural at 120 K with Z′ = 2: complex sheets built from N—H⋯O, C—H⋯O and C—H⋯π(arene) hydrogen bonds

Wardell, S.M.S.V. — 2006-03-15

At 120 K, 2,4-difluorobenzaldehyde benzoylhydrazone, C14H10F2N2O, (I), and 2,4-dichlorobenzaldehyde benzoylhydrazone, C14H10Cl2N2O, (II), are isomorphous and isostructural in P21/n with Z′ = 2. In each structure, eight independent hydrogen bonds, viz. two of N—H⋯O type, five of C—H⋯O type and one of C—H⋯π(arene) type, link the molecules into complex sheets, within which two independent one-dimensional substructures can be identified.

Insights into crystallization mechanism: a synchrotron study of polymorphism in a cobalt acetate cluster compound

Burley, J.C. — 2006-02-15

The structure of the title compound, di-μ3-acetato-1κ2O,O′:2κO′;2κO:3κ2O,O′-di-μ2-acetato-1κO:2κO′;2κO:3κO′-octapyridyl-1κ3N,2κ2N,3κ3N-tricobalt(II) bis(hexafluorophosphate), [Co3(C2H3O2)4(C5H5N)8](PF6)2, consists of divalent multinuclear cations in which three CoII ions are bridged by four μ2-acetate groups. The CoII ions are arranged in an approximately linear manner. The bridging acetates adopt two distinct coordination geometries: one pair bridges via a single O atom and the other pair employs both O atoms. The coordination octahedron around each CoII ion is completed by three pyridine molecules for the two outer CoII ions and by two for the inner ion. Charge is balanced by two PF6− anions. Single-crystal synchrotron X-ray studies indicate the existence of two polymorphs, both triclinic, which are distinguished primarily by differences in the relative orientations of the multinuclear cations, which in form 1 are tilted with respect to each other, but in form 2 are co-parallel as a result of the central Co atom lying on an inversion centre. The results of the structural studies allow an insight into the crystallization mechanism and resultant polymorphism. They suggest that a (bidentate carboxyl)C—O⋯H—C(pyridine) interaction exists in solution. For form 1, crystallized from pyridine, the interaction is not structure determining, as it is satisfied by interactions between solvent and solute. For form 2, crystallized from CH2Cl2, the interaction is between a bound acetate carboxyl group on one cation and a bound pyridine on another and is thus structure directing.

Pyrrole-2-carbaldehyde isonicotinoylhydrazone monohydrate redetermined at 120 K

Wardell, S.M.S.V. — 2006-01-15

In the title compound, C11H10N4O·H2O, there are five independent hydrogen bonds, of O—H⋯O, O—H⋯N and N—H⋯O types, which link the components into complex sheets parallel to (001).

3-(3-Nitrophenylaminocarbonyl)propionic acid: hydrogen-bonded sheets of alternating R22(8) and R66(36) rings

Wardell, J.L. — 2006-01-15

Molecules of the title compound, C10H10N2O5, are linked by a combination of O—H⋯O and N—H⋯O hydrogen bonds into (100) sheets containing alternating R22(8) and R66(36) rings.

2-Amino-5-trifluoromethyl-1,3,4-thiadiazole and a redetermination of 2-amino-1,3,4-thiadiazole, both at 120 K: chains of edge-fused R22(8) and R44(10) rings, and sheets of R22(8) and R66(20) rings

Boechat, N. — 2006-01-15

Molecules of 2-amino-5-trifluoromethyl-1,3,4-thiadiazole, C3H2F3N3S, are linked by two independent N—H⋯N hydrogen bonds into sheets of alternating R22(8) and R66(20) rings, while the molecules of the unsubstituted 2-amino-1,3,4-thiadiazole, C2H3N3S, are linked, again by two independent N—H⋯N hydrogen bonds, but into chains of edge-fused R22(8) and R44(10) rings.

1,5-Bis(4-chlorophenyl)-3-(2-chloroquinolin-3-yl)pentane-1,5-dione: sheets of R44(26) rings built from C—H⋯N and C—H⋯O hydrogen bonds

Insuasty, B. — 2006-01-15

Molecules of the title compound, C26H18Cl3NO2, are linked into sheets of R44(26) rings by a combination of C—H⋯N and C—H⋯O hydrogen bonds.

Simple chains in methyl 3,5-dinitrobenzoate, isolated molecules in isopropyl 3,5-dinitrobenzoate, and a three-dimensional framework containing double and sextuple helices in benzyl 3,5-dinitrobenzoate, all at 120 K

Vasconcelos, T.R.A. — 2006-01-15

Molecules of methyl 3,5-dinitrobenzoate, C8H6N2O6, are linked into C(7) chains by a single nearly linear C—H⋯O hydrogen bond, but there are no direction-specific interactions in the structure of isopropyl 3,5-dinitrobenzoate, C10H10N2O6. In benzyl 3,5-dinitrobenzoate, C14H10N2O6, the molecules are linked by four independent C—H⋯O hydrogen bonds into a complex three-dimensional framework structure, in which it is possible to identify simple substructures in the form of cyclic centrosymmetric dimers, double helices and sextuple helices.

5-Chloro-3-methyl-4-[3-(4-nitrophenyl)-4,5-dihydro-1H-pyrazol-5-yl]-1-phenyl-1H-pyrazole: a chain of fused hydrogen-bonded rings

Insuasty, B. — 2006-01-15

In the title compound, C19H16ClN5O2, the molecules are linked into chains of edge-fused rings by a combination of two independent C—H⋯O hydrogen bonds, augmented by a centrosymmetric π–π stacking interaction.

Hydrogen-bonding patterns in trimethoprim picolinate and 2-amino-4,6-dimethylpyrimidinium picolinate hemihydrate

Hemamalini, M. — 2006-02-15

In the title compounds, namely 2,4-diamino-5-[(3,4,5-trimethoxyphenyl)methyl]pyrimidin-1-ium pyridine-2-carboxylate, C14H19N4O3+·C6H4NO2−, (I), and 2-amino-4,6-dimethylpyrimidin-1-ium pyridine-2-carboxylate hemihydrate, C6H10N3+·C6H4NO2−·0.5H2O, (II), the trimethoprim and 2-amino-4,6-dimethylpyrimidin-1-ium cations are protonated at one of the pyrimidine N atoms. In (I), bifurcated hydrogen bonds are observed between a picolinate O atom, the protonated N atom and the 2-amino group; the graph-set designator is R21(6). The pyrimidine moieties of the trimethoprim cations are centrosymmetrically paired through a pair of N—H⋯N hydrogen bonds. In addition to the base pairing, one of the picolinate O atoms bridges the 2- and 4-amino groups on either side of the paired bases, resulting in a complementary DADA array. In (II), the carboxylate group of the picolinate anion binds with the protonated pyrimidine N atom and the 2-amino group of the pyrimidine moiety through a pair of N—H⋯O hydrogen bonds, leading to the common ring motif R22(8). The water molecule, which resides on a twofold rotation axis, bridges the carboxylate group of the picolinate anion via O—H⋯O hydrogen bonds.

Hydrogen-bonded supramolecular structures of three related 4-(5-nitro-2-furyl)-1,4-dihydropyridines

Quesada, A. — 2006-01-15

In ethyl 5-cyano-2,6-dimethyl-4-(5-nitro-2-furyl)-1,4-dihydropyridine-3-carboxylate, C15H15N3O5, the molecules are linked into chains by a single N—H⋯O hydrogen bond. The molecules in diethyl 2,6-dimethyl-4-(5-nitro-2-furyl)-1,4-dihydropyridine-3,5-dicarboxylate, C17H20N2O7, are linked by a combination of one N—H⋯O hydrogen bond and two C—H⋯O hydrogen bonds into sheets built from equal numbers of R22(17) and R44(18) rings. In 2,6-dimethyl-4-(5-nitro-2-furyl)-1,4-dihydropyridine-3,5-dicarbonitrile, C13H10N4O3, the molecules are linked by a combination of a three-centre N—H⋯(O)2 hydrogen bond and two independent two-centre C—H⋯O hydrogen bonds into complex sheets containing four types of ring.

Do C—H⋯O and C—H⋯π interactions help to stabilize a non-centrosymmetric structure for racemic 2,3-dibromo-1,3-diphenylpropan-1-one?

Harrison, W.T.A. — 2005-12-15

The racemic title compound, C15H12Br2O, crystallizes in a non-centrosymmetric structure and displays a significant non-linear optical response to red light. The crystal packing is influenced by C—H⋯O and C—H⋯π interactions. One of the former bonds has a short H⋯O separation of 2.27 Å.

Hydrogen-bonding and carbonyl–carbonyl interactions in violuric acid methanol solvate

Nichol, G.S. — 2005-12-15

Violuric acid [systematic name: pyrimidine-2,4,5,6(1H,3H)-tetrone 5-oxime] crystallized from a methanol solution stored at approximately 278 K as a monosolvate, C4H3N3O4·CH3OH, in the form of very small and fragile needles. Synchrotron radiation was needed to collect an adequate data set. Analysis of the crystal structure reveals that the isonitroso group of violuric acid is disordered over two positions with refined occupancies of approximately 3:1 for the major and minor disorder components. This fact has some important consequences for the hydrogen-bonding motifs found in the crystal packing, which are different for each component, although the overall packing pattern does not change. The crystal packing consists of closely stacked hydrogen-bonded sheets. Between the sheets are found carbonyl–carbonyl dipolar interactions, which are the principal intermolecular forces holding the sheets together.

Three-dimensional supramolecular structures in (E,E)-N,N′-bis(4-nitrobenzylidene)butane-1,4-diamine and (E,E)-N,N′-bis(4-nitrobenzylidene)hexane-1,6-diamine

Glidewell, C. — 2006-01-15

In both (E,E)-N,N′-bis(4-nitrobenzylidene)butane-1,4-diamine, C18H18N4O4, (III), and (E,E)-N,N′-bis(4-nitrobenzylidene)hexane-1,6-diamine, C20H22N4O4, (IV), the molecules lie across centres of inversion in space groups P\overline{1} and P21/c, respectively. In (III), the three-dimensional supramolecular structure is built from π-stacked chains of edge-fused R22(30) rings, while in (IV), chains of edge-fused R22(38) rings are linked by dipolar nitro–nitro interactions.

1,2,3,4-Tetra-O-acetyl-β-d-glucopyranuronic acid monohydrate at 120 K and anhydrous 1,2,3,4-tetra-O-acetyl-β-d-glucopyranose at 292 K

Baddeley, T.C. — 2005-12-15

The structure of the title acid as the monohydrate, C14H18O11·H2O, displays hydrogen bonding which connects the molecules in layers parallel to (10\overline{1}). In the anhydrous glucopyranose, C14H20O10, only chain connectivity is attained but, due to disorder of the OH group, only partially and in two modes, one less favoured than the other. This provides incomplete connectivity between molecules in corrugated layers parallel to (010).

Bis[(2-pyridyl)(2-pyridylamino)methanolato]cobalt(III) perchlorate: a consequence of cobalt ion-assisted oxidative deamination of a tris(pyridyl)aminal ligand

Adams, H. — 2005-12-15

The title compound, [Co(C11H10N3O)2]ClO4, designated [Co(L2)2]ClO4, was synthesized by reaction of CoII with two molar equivalents of (2-pyridyl)bis(2-pyridylamino)methane (L1) under ambient conditions, whereby the divalent metal ion was oxidized concomitantly with oxygenation and deamination of the aminal polydentate ligand to generate the tridentate ligand anion (2-pyridyl)(2-pyridylamino)methanolate, L2−. In the X-ray crystal structure of the complex cation, [Co(L2)2]+, the two L2− ligands are coordinated to the central cobalt(III) metal ion in a facial mode to afford a pseudo-octahedral geometry. The four pyridyl N atoms constitute the equatorial plane on which the cobalt(III) ion lies; the methanolate O atoms occupy the axial positions.

2-(3-Nitrophenylaminocarbonyl)benzoic acid: hydrogen-bonded sheets of R44(22) rings

Glidewell, C. — 2006-01-15

In the title compound, C14H10N2O5, the molecules are linked by a combination of one N—H⋯O and one O—H⋯O hydrogen bond into sheets containing a single type of R44(22) ring.

Four nitrobenzaldehyde isonicotinoylhydrazones at 120 K: four different supramolecular structures in two and three dimensions

Wardell, S.M.S.V. — 2005-12-15

The molecules of 2-nitrobenzaldehyde isonicotinoylhydrazone, C13H10N4O3, (I), are linked into a three-dimensional framework by a combination of one N—H⋯N and three C—H⋯O hydrogen bonds. In the isomeric compound 3-nitrobenzaldehyde isonicotinoylhydrazone, (II), the molecules are linked into complex sheets by a combination of three hydrogen bonds, one each of the N—H⋯N, C—H⋯N and C—H⋯O types. The molecules of the third isomer, namely 4-nitrobenzaldehyde isonicotinoylhydrazone, (III), are linked into bilayers by a combination of one N—H⋯N, one C—H⋯N and two C—H⋯O hydrogen bonds. 2,4-Dinitrobenzaldehyde isonicotinoylhydrazone, (IV), crystallizes as a stoichiometric monohydrate, C13H9N5O5·H2O, and the molecular components are linked into a three-dimensional framework by a combination of O—H⋯O, O—H⋯N, N—H⋯O and three independent C—H⋯O hydrogen bonds.

Proton sharing in bis(4-carbamoylpyridinium) squarate

Köroglu, A. — 2005-12-15

Reaction in aqueous solution of nickel(II) squarate with isonicotinamide yielded well formed yellow crystals of the title compound, 2C6H6N2O+·C4O42−, as a side product. The squarate dianion is bisected by a crystallographic twofold rotation axis, which passes through the centres of two opposite bonds of the ring. Crystal structure analysis reveals that, far from forming discrete ionic species, it is likely that there is a large degree of proton sharing between the anion and cation, with the H atom lying almost symmetrically between the donor and acceptor sites, as evidenced by the long N—H and short H⋯O distances [1.15 (3) and 1.39 (3) Å, respectively]. Other hydrogen bonding is more conventional, and there are weaker C—H⋯O interactions contributing additional stability to the structure.

Methylammonium antimony sulfide

Lees, R.J.E. — 2005-12-15

Bis(methylammonium) octaantimony(III) dodecasulfide persulfide, (CH3NH3)2[Sb8S12(S2)], contains pairs of [Sb4S7]2− chains joined through an unusual persulfide bond to create infinite double [Sb8S14]2− chains. The double chains are interlocked by longer Sb⋯S interactions to form sheets approximately parallel to the (101) crystallographic plane. Methylammonium cations, formed by decomposition of 2-methylpropane-1,2-diamine during the synthesis, are located in large (Sb8S10) hetero-ring apertures created within the double chains.

N-Benzylethylammonium nitrate: a three-dimensional hydrogen-bonded framework comprising substructures in zero, one and two dimensions

Abonia, R. — 2005-11-15

The title compound is a salt, C9H14N+·NO3−, in which two N—H⋯O hydrogen bonds and two C—H⋯O hydrogen bonds generate a three-dimensional framework structure. The combination of one N—H⋯O hydrogen bond and one C—H⋯O hydrogen bond generates a finite (zero-dimensional) centrosymmetric R44(14) aggregate containing two cations and two anions; the combination of the two N—H⋯O hydrogen bonds generates a one-dimensional C22(6) chain of alternating cations and anions, and the combination of one N—H⋯O hydrogen bond and two C—H⋯O hydrogen bonds generates a two-dimensional sheet of alternating R44(14) and R86(34) rings.

Dichlorotetrakis[3-(4-pyridyl)-1H-pyrazole]cobalt(II) acetonitrile tetrasolvate: an infinite hydrogen-bonded network, in an instant

Davies, G.M. — 2005-11-15

Reaction of 3-(4-pyridyl)pyrazole (4pypz) with cobalt(II) chloride in acetonitrile affords the title complex, [CoCl2(C8H7N3)4]·4CH3CN, within seconds of addition, as purple X-ray quality crystals. The molecule has C4 symmetry. The metal ion exhibits a trans-N4Cl2 octahedral geometry, with the four 3-(4-pyridyl)-1H-pyrazole ligands coordinating through their pyridyl N-atom donors; one coordinated chloride ion forms hydrogen bonds with the pyrazole rings from four separate units. This configuration creates an infinite three-dimensional coordination network containing channels that are filled with acetonitrile solvent molecules.

Contrasting three-dimensional framework structures in the isomeric pair 2-iodo-N-(2-nitrophenyl)benzamide and N-(2-iodophenyl)-2-nitrobenzamide

Wardell, J.L. — 2005-11-15

In 2-iodo-N-(2-nitrophenyl)benzamide, C13H9IN2O3, the molecules are linked into a three-dimensional framework structure by a combination of a C—H⋯O hydrogen bond, and iodo–nitro, carbonyl–carbonyl and aromatic π–π stacking interactions. In the isomeric compound N-(2-iodophenyl)-2-nitrobenzamide, the framework structure is built from N—H⋯O, C—H⋯O and C—H⋯π(arene) hydrogen bonds and an iodo–nitro interaction.

Polymorphism in an unexpected caesium complex of 5-hydroxyhydurilic acid

Nichol, G.S. — 2005-10-15

Vigorous reaction of barbituric acid with caesium hydroxide in water resulted in an unexpected coupling product, 5-hydroxyhydurilic acid, complexed to caesium, giving poly[[caesium-μ5-5-hydroxyhydurilato] hemihydrate], {[Cs(C8H5N4O7)]·0.5H2O}n. This was obtained in two different polymorphic forms, depending on the method of crystal growth. Slow solvent evaporation yielded an orthorhombic polymorph, (I), which crystallized in the space group Pnab (non-standard setting of Pbcn), with the uncoordinated water molecule lying on a crystallographic twofold axis. The water molecule is sandwiched into cavities within the structure and is securely held in place by N—H⋯O and O—H⋯O hydrogen bonding. Polymorph (II) is monoclinic, although the unit-cell parameters are similar to those of polymorph (I), and it crystallizes in the space group C2/c, with the uncoordinated water molecule again lying on the twofold axis and secured by hydrogen bonding. The differences between the two polymorphs, both of which have nine-coordinate caesium and a similar first-shell environment of all structural components, are in the overall arrangement of the cations, anions and water molecules, and in the shape of the cavities, revealed by inspecting and comparing crystal-packing diagrams.

π-Stacked hydrogen-bonded chains of rings in 2,4-difluorobenzaldehyde isonicotinoylhydrazone and hydrogen-bonded sheets in 2,3-dichlorobenzaldehyde isonicotinoylhydrazone

Wardell, S.M.S.V. — 2005-10-15

The difluorinated ring in 2,4-difluorobenzaldehyde isonicotinoylhydrazone, C13H9F2N3O, (I), is disordered over two sets of sites with unequal occupancy. The molecules of (I) are linked by a combination of N—H⋯O and C—H⋯O hydrogen bonds into chains of rings, which are linked into sheets by a single π–π stacking interaction. In 2,3-dichlorobenzaldehyde isonicotinoylhydrazone, C13H9Cl2N3O, (II), the molecules are linked by a combination of N—H⋯N, C—H⋯N and C—H⋯O hydrogen bonds into sheets of R44(14) and R44(26) rings.

Three isomeric (E)-nitrobenzaldehyde nitrophenylhydrazones: chains of rings in isomorphous (E)-2-nitrobenzaldehyde 3-nitrophenylhydrazone and (E)-3-nitrobenzaldehyde 2-nitrophenylhydrazone, and centrosymmetric dimers in (E)-4-nitrobenzaldehyde 2-nitrophenylhydrazone

Ferguson, G. — 2005-10-15

The isomeric compounds (E)-2-nitrobenzaldehyde 3-nitrophenylhydrazone and (E)-3-nitrobenzaldehyde 2-nitrophenylhydrazone, both C13H10N4O4, are isomorphous and effectively isostructural, and in both, the molecules are disordered across centres of inversion in the space group P21/c. The molecules are linked into complex chains of rings by N—H⋯O and C—H⋯O hydrogen bonds. In the isomeric compound (E)-4-nitrobenzaldehyde 2-nitrophenylhydrazone, the fully ordered molecules are linked by N—H⋯O hydrogen bonds into centrosymmetric dimers.

A second polymorph of 2-aminopyridinium dihydrogenphosphate

Demir, S. — 2005-09-15

In the title compound, β-C5H7N2+·H2PO4−, the tetrahedral dihydrogenphosphate moieties are linked into double chains by O—H⋯O hydrogen bonds, and the organic species crosslink the chains into sheets by way of N—H⋯O bonds. The resulting structure is quite different from that of the previously described α polymorph of this stoichiometry [Czapla, Dacko & Waskowska (2003). J. Phys. Condens. Matter, 15, 3793–3803].

(1RS,2RS)-N,N′-Bis(4-nitrophenylmethylene)cyclohexane-1,2-diamine: complex sheets built from C—H⋯O and C—H⋯π(arene) hydrogen bonds

Glidewell, C. — 2005-09-15

The racemic title compound, C20H20N4O4, crystallizes with Z′ = 2 in the space group P21/c. Each independent molecule exhibits approximate twofold rotation symmetry, but conformational differences between the molecules preclude any higher symmetry. The molecules are linked into complex sheets by a combination of four C—H⋯O hydrogen bonds and two C—H⋯π(arene) hydrogen bonds.

N-(6-Amino-3,4-dihydro-3-methyl-5-nitroso-4-oxopyrimidin-2-yl)leucine: a three-dimensional hydrogen-bonded framework structure

Arranz Mascarós, P. — 2005-09-15

In the title compound, C11H17N5O4, the bond distances show evidence of a highly polarized molecular–electronic structure. The molecules are linked into a three-dimensional framework by a combination of O—H⋯O and N—H⋯O hydrogen bonds, including a very short O—H⋯O hydrogen bond [H⋯O = 1.67 Å, O⋯O = 2.494 (2) Å and O—H⋯O = 166°].

Twisted [(R3P)PdX] groups above dicarbaborane ligands: 4-dimethylsulfido-3-iodo-3-triphenylphosphine-closo-3-pallada-1,2-dicarbadodecaborane and 3-dimethylphenylphosphine-3-chloro-4-dimethylsulfido-closo-3-pallada-1,2-dicarbadodecaborane

Ferguson, G. — 2005-08-15

The structural analyses of [3-(PPh3)-3-I-4-(SMe2)-closo-3,1,2-PdC2B9H10] or [Pd(C4H16B9S)I(C18H15P)], (I), and [3-(PPhMe2)-3-Cl-4-(SMe2)-closo-3,1,2-PdC2B9H10] or [Pd(C4H16B9S)Cl(C8H11P)], (II), show that in comparison with [3-(PR3)2-closo-3,1,2-PdC2B9H11] the presence of the 4-SMe2 group causes the [PdX(PR3)] unit (X = halogen) to twist about an axis passing through the Pd atom and the directly opposite B atom of the carbaborane ligand. The halogen atoms are located almost directly above a C atom in the C2B3 face, and the conformations of the [PdX(PR3)] units above the C2B3 faces are not those predicted from molecular orbital calculations of the closo-3,1,2-PdC2B9 system. The fact that the variation from the predicted conformation is greater in the case of (I) than in (II) may be ascribed to the greater steric interactions induced by the I atom in (I) compared with the Cl atom in (II).

Two isomeric 10-methyl-8-phenyl-11-pyridyl-6,8-dihydro-5H-benzo[f]pyrazolo[3,4-b]quinolines: cyclic hydrogen-bonded tetramers versus isolated molecules

Portilla, J. — 2005-08-15

The molecules of 10-methyl-8-phenyl-11-(3-pyridyl)-6,8-dihydro-5H-benzo[f]pyrazolo[3,4-b]quinoline, C26H20N4, (I), are linked by a single C—H⋯N hydrogen bond into cyclic R{_4^4}(12) tetramers generated by a \overline{4} axis. In isomeric 10-methyl-8-phenyl-11-(4-pyridyl)-6,8-dihydro-5H-benzo[f]pyrazolo[3,4-b]quinoline, (II), which crystallizes with Z′ = 2 in space group P21212, the two independent molecules are nearly enantiomeric but there are no direction-specific interactions between them.

Supramolecular structures of four (Z)-5-arylmethylene-2-thioxothiazolidin-4-ones: hydrogen-bonded dimers, chains of rings and sheets

Delgado, P. — 2005-08-15

In each of the four title compounds, namely (Z)-5-benzylidene-2-thioxothiazolidin-4-one, C10H7NOS2, (I), which crystallizes with Z′ = 2 in space group P21/n, (Z)-5-(4-methylbenzylidene)-2-thioxothiazolidin-4-one, C11H9NOS2, (II), (Z)-2-thioxo-5-[4-(trifluoromethyl)benzylidene]thiazolidin-4-one, C11H6F3NOS2, (III), and (Z)-5-(4-methoxybenzylidene)-2-thioxothiazolidin-4-one, C11H9NO2S2, (IV), there is a very wide C—C—C angle (ca 130°) at the methine C atom linking the two rings. Pairs of N—H⋯O hydrogen bonds link the two independent molecules in (I) into a cyclic dimeric unit, and these units are further linked into complex sheets by three independent C—H⋯π(arene) hydrogen bonds. The molecules of (II) are linked by paired N—H⋯O hydrogen bonds into centrosymmetric R22(8) dimers; the molecules of (III) and (IV) are linked into chains of rings, which are constructed from a combination of N—H⋯S and C—H⋯O hydrogen bonds in (III), and from a combination of N—H⋯O and C—H⋯S hydrogen bonds in (IV).

Glyoxal 4-nitrophenylhydrazone: triple helices linked into a three-dimensional channel structure

Glidewell, C. — 2005-08-15

The molecules of the title compound, C8H7N3O3, which are nearly planar, are linked by an N—H⋯O hydrogen bond into helical chains, three of which are required to define the structure completely. These triply intertwined helices are linked by a C—H⋯O hydrogen bond into a three-dimensional framework enclosing two distinct types of channel, with average cross-sectional areas of 15.0 and 8.2 Å2.

Effect of substitution on the dimensionality of supramolecular aggregation in dihydrobenzopyrazoloquinolines

Portilla, J. — 2005-08-15

Molecules of 8-methyl-10-phenyl-6,10-dihydro-5H-benzo[h]pyrazolo[3,4-b]quinoline, C21H17N3, (I), are linked into cyclic centrosymmetric dimers by means of paired C—H⋯N hydrogen bonds. In each of 8-methyl-7,10-diphenyl-6,10-dihydro-5H-benzo[h]pyrazolo[3,4-b]quinoline, C27H21N3, (II), and 8-methyl-7-(4-methylphenyl)-10-phenyl-6,10-dihydro-5H-benzo[h]pyrazolo[3,4-b]quinoline, C28H23N3, (III), the molecules are linked by C—H⋯π(arene) hydrogen bonds into sheets, although the detailed construction of the sheets is entirely different in (II) and (III). The molecules of 7-(4-methoxyphenyl)-8-methyl-10-phenyl-6,10-dihydro-5H-benzo[h]pyrazolo[3,4-b]quinoline, C28H23N3O, (IV), are linked into a complex three-dimensional framework structure by a combination of C—H⋯N, C—H⋯O and three independent C—H⋯π(arene) hydrogen bonds.

2-(2-Pyridyl)pyridinium perchlorate, redetermined at 120 K: complex hydrogen-bonded sheets

Kavitha, S.J. — 2005-08-15

In the title compound, C10H9N2+·ClO4−, the ions are linked into complex sheets by the combination of one N—H⋯O and four independent C—H⋯O hydrogen bonds.

Thallium(III) selenite, Tl2(SeO3)3

Harrison, W.T.A. — 2005-07-15

The structure of Tl2(SeO3)3 [dithallium(III) triselenium(IV) nonaoxide] is monoclinic (P21/n symmetry), with all atoms in general positions. It is built up from TlO6 octahedra, distorted TlO7 pentagonal bipyramids and (SeO3)2− pyramids sharing vertices and edges to form corrugated (001) layers. The Se lone pairs of electrons are accommodated in the interlayer regions.

Ethylenediaminium niobium oxyfluoride

Stephens, N.F. — 2005-07-15

The title compound, bis(ethylenediaminium) μ-oxo-bis[tetrafluorooxoniobium(V)], (C2H10N2)2[Nb2O3F8], is a novel organically templated niobium oxyfluoride. It consists of isolated [Nb2O3F8]4− octahedral dimers charge balanced by ethylenediaminium cations, two of which lie about inversion centres. Two NbO2F4 octahedra are fused through a common O atom to form the dimers. Characteristic short terminal Nb=O bond lengths and longer Nb—F and bridging Nb—O bond lengths are observed, which result in the out-of-centre distortion of the octahedra, a manifestation of the second-order Jahn–Teller effect. Extensive hydrogen bonding between the dimers and the organic template is exhibited.

Methyl 2-(4-ferrocenylbenzamido)thiophene-3-carboxylate and ethyl 2-(4-ferrocenylbenzamido)-1,3-thiazole-4-acetate, a unique ferrocene derivative containing a thiazole moiety

Alley, S. — 2005-07-15

The conformations and hydrogen bonding in the thiophene and thiazole title compounds, [Fe(C5H5)(C20H14NO3S)], (I), and [Fe(C5H5)(C19H17N2O3S)], (II), are discussed. The sequence (C5H4)–(C6H4)–(CONH)–(C4H2S)–(CO2Me) of rings and moieties in (I) is close to being planar; all consecutive interplanar angles are less than 10°. An intramolecular N—H⋯O=Cester hydrogen bond [graph set S(6), N⋯O = 2.768 (2) Å and N—H⋯O = 134 (2)°] effects the molecular planarity, and aggregation occurs via hydrogen-bonded chains formed from intermolecular Car—H⋯O=Cester/amide interactions along [010], with C⋯O distances ranging from 3.401 (3) to 3.577 (2) Å. The thiazole system in (II) crystallizes with two molecules in the asymmetric unit; these differ in the conformation along their long molecular axes; for example, the interplanar angle between the phenylene (C6H4) and thiazole (C3NS) rings is 8.1 (2)° in one molecule and 27.66 (14)° in the other. Intermolecular N—H⋯O=Cester hydrogen bonds [N⋯O = 2.972 (4) and 2.971 (3) Å], each augmented by a Cphenylene—H⋯O=Cester interaction [3.184 (5) and 3.395 (4) Å], form motifs with graph set R_{2}^{1}(7) and generate chains along [100]. The amide C=O groups do not participate in hydrogen bonding. Compound (II) is the first reported ferrocenyl-containing thiazole structure.

A mixed iron(III)/lithium alkoxide

Barley, H.R.L. — 2005-07-15

The heterometallic alkoxide catena-poly[[tetra-μ2-tert-butoxo-1:2κ4O:O;1:3κ4O:O-bis(tetrahydrofuran)-2κO,3κO-iron(III)dilithium(I)]-μ-bromo], [FeLi2Br(C4H9O)4(C4H8O)2]n, forms a one-dimensional chain through an a-glide. This conformation is achieved through the formation of FeIII/O/Li/O rings and Li—Br—Li bridges.

2-Iodo-N-(4-nitrophenyl)benzamide forms hydrogen-bonded sheets of R44(24) rings

Garden, S.J. — 2005-07-15

Molecules of the title compound, C13H9IN2O3, are linked into C(4) chains by an N—H⋯O=C hydrogen bond, and these chains are linked into sheets of R44(24) rings by means of a C—H⋯O—N hydrogen bond. However, C—H⋯π(arene) hydrogen bonds, and π–π stacking and iodo–nitro interactions are all absent.

Hydrogen-bonded chains in isostructural 5-methyl-2-(4-methylphenyl)-7,8-dihydro-6H-cyclopenta[g]pyrazolo[1,5-a]pyrimidine, 2-(4-chlorophenyl)-5-methyl-7,8-dihydro-6H-cyclopenta[g]pyrazolo[1,5-a]pyrimidine and 2-(4-bromophenyl)-5-methyl-7,8-dihydro-6H-cyclopenta[g]pyrazolo[1,5-a]pyrimidine, and sheets of π-stacked hydrogen-bonded chains in 2-(4-methoxyphenyl)-5-methyl-7,8-dihydro-6H-cyclopenta[g]pyrazolo[1,5-a]pyrimidine

Portilla, J. — 2005-07-15

5-Methyl-2-(4-methylphenyl)-7,8-dihydro-6H-cyclopenta[g]pyrazolo[1,5-a]pyrimidine, C17H17N3, 2-(4-chlorophenyl)-5-methyl-7,8-dihydro-6H-cyclopenta[g]pyrazolo[1,5-a]pyrimidine, C16H14ClN3, and 2-(4-bromophenyl)-5-methyl-7,8-dihydro-6H-cyclopenta[g]pyrazolo[1,5-a]pyrimidine, C16H14BrN3, are isostructural; in each compound, the molecules are linked into chains by a single C—H⋯π(arene) hydrogen bond. Molecules of 2-(4-methoxyphenyl)-5-methyl-7,8-dihydro-6H-cyclopenta[g]pyrazolo[1,5-a]pyrimidine, C17H17N3O, are linked by a single C—H⋯N hydrogen bond into chains, which are themselves linked into sheets by a π–π stacking interaction.

A monoclinic polymorph of 3,7,7-trimethyl-1-phenyl-5,6,7,8-tetrahydro-1H-pyrazolo[3,4-b]quinolin-5-one

Mera, J. — 2005-07-15

A second, monoclinic, polymorph of the title compound, C19H19N3O, is reported. In this polymorph, the molecules are linked into chains by paired C—H⋯π hydrogen bonds and the chains are linked into sheets by π stacking interactions.

Solvent-dependent polymorphism in isomeric N-(nitrobenzylidene)iodoanilines

Ferguson, G. — 2005-07-15

Three of the nine isomeric N-(nitrobenzylidene)iodoanilines, C13H9IN2O2, have been found, when crystallized from acetone, to yield polymorphs which differ from those obtained upon crystallization from ethanol. In the second polymorph of 2-iodo-N-(2-nitrobenzylidene)aniline, the molecules are disordered across inversion centres in space group C2/c, but there are no direction-specific interactions between the molecules. In the second polymorph of 2-iodo-N-(3-nitrobenzylidene)aniline, the molecules adopt a different conformation from those in the first polymorph, and they are linked into sheets by a combination of a three-centre iodo–nitro interaction and an aromatic π–π stacking interaction, both of which are absent from the supramolecular structure of the first polymorph. The second polymorph of 3-iodo-N-(2-nitrobenzylidene)aniline crystallizes with Z′ = 2 in space group P21, and the molecules are linked into sheets by one C—H⋯O hydrogen bond and two C—H⋯π(arene) hydrogen bonds.

1λ4,4λ4,8λ4,11λ4-Tetrathiacyclotetradecane-1,4,7,10-tetraylidenetetraaminium tetrakis(2,4,6-trimethylbenzenesulfonate)

Dale, S.H. — 2005-06-15

Investigations of the reactivity of the thio-crown [14]aneS4 (1,4,8,11-tetrathiacyclotetradecane) towards the aminating agent o-mesitylsulfonylhydroxylamine have lead to the crystallization of 1λ4,4λ4,8λ4,11λ4-tetrathiacyclotetradecane-1,4,7,10-tetraylidenetetraaminium tetrakis(2,4,6-trimethylbenzenesulfonate), C10H28N4S44+·4C9H11O3S−. The compound crystallizes in a centrosymmetric space group, with half a formula unit in the asymmetric unit. All S atoms within the cationic component are aminated, with the four NH2 substituents arranged in pairs on neighbouring S atoms on opposite faces of the crown. The macrocyclic cation in the compound forms hydrogen bonds with the 2,4,6-trimethylbenzenesulfonate anions to create chains, which are further linked into thick two-dimensional sheets.

Hydrogen-bonded chains in 3-(5-chloro-3-methyl-1-phenyl-1H-pyrazol-4-yl)-1-(4-methoxyphenyl)propenone and 3-(5-chloro-3-methyl-1-phenyl-1H-pyrazol-4-yl)-1-(3,4,5-trimethoxyphenyl)propenone

Trilleras, J. — 2005-06-15

Molecules of 3-(5-chloro-3-methyl-1-phenyl-1H-pyrazol-4-yl)-1-(4-methoxyphenyl)propenone, C20H17ClN2O2, (I), are linked into C(10) chains and molecules of 3-(5-chloro-3-methyl-1-phenyl-1H-pyrazol-4-yl)-1-(3,4,5-trimethoxyphenyl)propenone, C22H21ClN2O4, (II), are linked into C(14) chains, in each case by means of a single C—H⋯O hydrogen bond.

B—N bond cleavage by cobalt(II) in acetato(3,5-diphenylpyrazole)[tris(3,5-diphenylpyrazolyl)borato]cobalt(II)

Harding, D.J. — 2005-06-15

The reaction of cobalt(II) acetate with potassium tris(pyrazolyl)borate (KTpPh2) affords the title complex, [Co(TpPh2)(O2CMe)(HpzPh2)] (HpzPh2 is 3,5-diphenylpyrazole) or [Co(C45H34BN6)(C2H3O2)(C15H12N2)], as a result of cobalt-induced B—N bond cleavage of the tris(pyrazolyl)borate ligand. The cobalt complex exhibits a distorted CoN4O coordination geometry with a κ3-coordinated TpPh2 ligand and monodentate acetate and pyrazole ligands. In addition, the non-coordinated acetate O atom is involved in a weak intramolecular hydrogen-bonding interaction with the pyrrole NH group.

1-Benzyl-4-(4-nitrophenyl)-2,3-dihydro-1H-1,5-benzodiazepine: a three-dimensional framework structure generated by two C—H⋯O hydrogen bonds and one C—H⋯π(arene) hydrogen bond

Torres, H. — 2005-06-15

In the title compound, C22H19N3O2, the seven-membered ring adopts a boat conformation. The molecules are linked by a combination of two C—H⋯O hydrogen bonds and one C—H⋯π(arene) hydrogen bond into a complex three-dimensional framework structure; each individual hydrogen bond generates a one-dimensional substructure, and pairwise combinations of two hydrogen bonds generate a further set of three one-dimensional substructures.

Two isomeric pairs of dihydrobenzopyrazoloquinazolines: centrosymmetric dimers, chains and sheets built from C—H⋯N and C—H⋯π(arene) hydrogen bonds and π–π stacking interactions

Portilla, J. — 2005-06-15

Molecules of 5-methyl-2-phenyl-6,7-dihydrobenzo[h]pyrazolo[1,5-a]quinazoline, C21H17N3, (I), are linked into chains by a combination of a C—H⋯π(arene) hydrogen bond and a π–π stacking interaction; in the closely related 5-methyl-2-(4-methylphenyl)-6,7-dihydrobenzo[h]pyrazolo[1,5-a]quinazoline, C22H19N3, (II), there are no hydrogen bonds and the molecules are linked into centrosymmetric dimers by a π–π stacking interaction. 7-Methyl-10-phenyl-5,6-dihydrobenzo[h]pyrazolo[5,1-b]quinazoline, C21H17N3, (III), is isomeric with (I), and the molecules of (III) are linked into sheets by a combination of C—H⋯N and C—H⋯π(arene) hydrogen bonds. 7-Methyl-10-(4-methylphenyl)-5,6-dihydrobenzo[h]pyrazolo[5,1-b]quinazoline, C22H19N3, (IV), is isomeric with (II), and molecules of (IV) are linked into centrosymmetric dimers by a C—H⋯π(arene) hydrogen bond, augmented by π–π stacking interactions.

6-Methyl-2-pyridone: an elusive structure finally solved

Nichol, G.S. — 2005-06-15

The title compound, C6H7NO, crystallizes unsolvated from dry toluene after storage for several months at approximately 263 K. Synchrotron radiation was needed in order to carry out data collection because of the small size of the crystals obtained. There are four crystallographically independent molecules in the asymmetric unit. Packing diagrams show that the molecules are linked into infinite chains by hydrogen bonding; two of the four independent molecules link together to form a chain, while the other two molecules form chains involving only their own symmetry equivalents, giving a total of three crystallographically distinct chains in all. The chains are held together by weak π–π interactions. This structure provides conclusive proof that, in the absence of any other co-crystallized molecule or solvent, the compound exists in the solid state as the pyridone and not the pyridinol tautomer.

A 1:1 adduct of dl-threonine and arsenic acid

Wilkinson, H.S. — 2005-06-15

The title compound, dl-threonine–arsenic acid (1/1), C4H9NO3·H3AsO4, is an unusual adduct containing zwitterionic threonine and neutral arsenic acid molecules. The component species interact by way of N—H⋯O and O—H⋯O hydrogen bonds, leading to parallel [001] chains of threonine and arsenic acid molecules which are crosslinked by further O—H⋯O and N—H⋯O bonds, resulting in a three-dimensional network.

The (1RS,2RS,7RS,8RS)- and (1RS,2SR,7SR,8RS)-diastereoisomers of 8,9,11,12-tetrachloro-N-ethyltricyclo[6.2.2.02,7]dodeca-9,11-diene-1,10-dicarboximide

Grimley, F.M. — 2005-06-15

Two racemic diastereoisomers, C16H15Cl4NO2, of the title 1,4-photoadduct of N-ethyltetrachlorophthalimide with cyclohexene have been isolated and their stereostructures determined.

Hydrogen bonding in C-substituted nitroanilines: simple C(8) chains in 2-bromo-6-chloro-4-nitroaniline

Glidewell, C. — 2005-05-15

In the title compound, C6H4BrClN2O2, the Br and Cl substituents are disordered over two sites, and the intramolecular dimensions provide evidence for charge polarization. The molecules are linked into C(8) chains by a single N—H⋯O hydrogen bond.

A new polymorph and two inclusion compounds of 9,9′-spirobifluorene

Douthwaite, R.E. — 2005-05-15

Two new inclusion compounds of 9,9′-spirobifluorene (SBF) incorporating benzene [(I), C25H16·C6H6] and biphenyl [(II), C25H16·C12H10], and a new polymorph of SBF [(III), C25H16] are reported. All three exhibit C—H⋯π(arene) hydrogen bonds between adjacent SBF molecules. Compound (II) also contains biphenyl C—H to SBF π-arene interactions. Collectively, hydrogen bonding gives rise to a chain and a layered motif in compounds (I) and (II), respectively.

Supramolecular structures of three isomeric (E,E)-1-(2-iodophenyl)-4-(nitrophenyl)-2,3-diaza-1,3-butadienes: changes in intermolecular interactions consequent upon changes of substituent location

Glidewell, C. — 2005-05-15

The supramolecular structures of the three isomeric (E,E)-1-(2-iodophenyl)-4-(2/3/4-nitrophenyl)-2,3-diaza-1,3-butadienes, C14H10IN3O2, are compared. In the 2-nitro isomer, the molecules are disordered across centres of inversion in space group C2/c and are linked into chains by a two-centre iodo–nitro interaction. The molecules of the 3-nitro isomer are linked into a three-dimensional framework by a combination of C—H⋯O and C—H⋯I hydrogen bonds and aromatic π–π stacking interactions, while molecules of the 4-nitro isomer are linked into sheets by a C—H⋯O hydrogen bond and a two-centre iodo–nitro interaction.

Supramolecular structures of five 5-(arylmethylene)-1,3-dimethylpyrimidine-2,4,6(1H,3H,5H)-triones: isolated molecules, hydrogen-bonded chains and chains of fused hydrogen-bonded rings

Rezende, M.C. — 2005-05-15

In each of the five title compounds, namely 5-benzylidene-1,3-dimethylpyrimidine-2,4,6(1H,3H,5H)-trione, C13H12N2O3, (I), 5-(3-methoxybenzylidene)-1,3-dimethylpyrimidine-2,4,6(1H,3H,5H)-trione, C14H14N2O4, (II), 5-(4-methoxybenzylidene)-1,3-dimethylpyrimidine-2,4,6(1H,3H,5H)-trione, C14H14N2O4, (III), 5-[4-(dimethylamino)benzylidene]-1,3-dimethylpyrimidine-2,4,6(1H,3H,5H)-trione, C15H17N3O3, (IV), and 5-(3,5-di-tert-butyl-4-hydroxybenzylidene)-1,3-dimethylpyrimidine-2,4,6(1H,3H,5H)-trione, C21H28N2O4, (V), which crystallizes with Z′ = 2 in P\overline{1}, there is a very wide C—C—C angle at the methine C atom linking the two rings, ranging from 137.1 (2)° in (I) to 139.14 (14)° in (III). There is evidence for intramolecular charge separation in (IV) and, to a lesser degree, in (III). The molecules of (I)–(III) are linked by pairs of C—H⋯O hydrogen bonds into chains of edge-fused rings, with alternating R22(14) and R22(16) rings in (I), alternating R22(14) and R44(20) rings in (II), with two types of R22(16) rings alternating in (III). The molecules in (IV) are linked by a single C—H⋯O hydrogen bond into simple C(8) chains, but there are no direction-specific intermolecular interactions in (V).

catena-Poly[[[N-(4-amino-1,6-dihydro-1-methyl-5-nitroso-6-oxopyrimidin-2-yl)-(S)-glutamato]hexaaquabarium]-μ-N-(4-amino-1,6-dihydro-1-methyl-5-nitroso-6-oxopyrimidin-2-yl)-(S)-glutamato]: coordination polymer chains linked into a three-dimensional framework by N—H⋯O and O—H⋯O hydrogen bonds

López Garzón, R. — 2005-05-15

In the title complex, [Ba(C10H12N5O6)2(H2O)6]n, the Ba atom is nine-coordinated by six water ligands and three carboxylate O atoms. The Ba2+ cations and the anionic glutamate ligands form coordination polymer chains, and these chains are linked by pairs of N—H⋯O hydrogen bonds and pairs of O—H⋯O hydrogen bonds to form a continuous three-dimensional framework of cations and anions, which is reinforced by hydrogen bonds involving the water molecules.

5-Butyl-5-ethylbarbituric acid: a phase transition at low temperature

Nichol, G.S. — 2005-05-15

The room-temperature crystal structure of 5-butyl-5-ethylbarbituric acid (generally known as butobarbitone), C10H16N2O3, was reported in space group C2/c [Bideau (1971). C. R. Acad. Sci. Paris Ser. C, 272, 757–760]. A redetermination at 120 K using synchrotron radiation shows the space group at this temperature to be P21/n and not C2/c. There are two crystallographically independent molecules in the asymmetric unit, but no solvent. Reported issues concerning possible disorder of the molecule are addressed; the butyl substituent of one of the molecules adopts an unusual conformation in being not fully extended. A subsequent re-collection at room temperature shows that the space group is indeed C2/c (A2/a with the axes selected in this report), and so the crystal structure undergoes a phase change upon cooling to 120 K.

4-[Bis(4-hydroxy-3,5-dimethylphenyl)methyl]pyridinium chloride and bromide

Tamuly, C. — 2005-05-15

The isostructural title salts, 4-[bis(4-hydroxy-3,5-dimethylphenyl)methyl]pyridinium chloride and bromide, C22H24NO2+·Cl− and C22H24NO2+·Br−, exhibit extended hydrogen-bonded ribbons in the solid state. The halide ions form hydrogen bonds to the pyridinium NH+ group and to the phenol OH groups of the cation. These bonds are coplanar to within 0.1 Å and form a T configuration at the anion.

Bis(1,3-diphenylpropane-1,3-dionato-κ2O,O′){hydrotris[3-(2-pyridyl)pyrazol-1-yl]borato}praseodymium(III): another member of an unpredictable series

Davies, G.M. — 2005-05-15

Reaction of praseodymium(III) chloride with stoichometric quantities of dibenzoylmethane (Hdbm) and hydrotris[3-(2-pyridyl)pyrazol-1-yl]borate (Tp2py) affords the title complex, [Pr(C24H19BN9)(C15H11O4)2]. The lanthanide ion in this ternary complex exhibits an N6O4 ten-coordinate geometry arising from the five bidentate arms found on the anionic ligands. The structure is entirely different from those found in other lanthanide complexes with the same ligand set.

2-(2-Acetylamino-5-chlorophenyl)-2,2-difluoroethanoic acid and 2-(2-acetylamino-5-methylphenyl)-2,2-difluoroethanoic acid, and 2-(2-acetylaminophenyl)-2,2-difluoro-N-phenylacetamide and 2-(2-acetylaminophenyl)-N-(4-chlorophenyl)-2,2-difluoroacetamide: examples of variation in molecular packing and hydrogen-bonding motif induced by substituent change

Boechat, N. — 2005-05-15

Among the title compounds, viz. the acids C10H8ClF2NO3, (I), and C11H11F2NO3, (II), and the amides C14H14F2N2O2, (III), and C14H13ClF2N2O2, (IV), the change of substituent from Cl in (I) to methyl in (II) has a dramatic effect upon the hydrogen bonding between the molecules, which occur in layers in both cases. In the structures of (III) and (IV), hydrogen bonds connect the molecules to form chains, but the introduction of a chloro substituent in (IV) has a profound effect on the orientation of the molecules within the chains and the packing of the chains in the structure as a whole.

2-[Bis(pyrazol-1-yl)methyl]-4-tert-butyl-6-(phenylsulfanyl)phenol

Sylvestre, I. — 2005-05-15

The title compound, C23H24N4OS, contains a highly asymmetric bifurcated intramolecular hydrogen bond between the hydroxy group and two pyrazole N atoms. The compound associates into centrosymmetric dimers in the crystal through two unique C—H⋯π interactions, which are in turn linked into a (6,3)-network through an additional intermolecular C—H⋯N hydrogen bond.

Supramolecular structures of four isomorphous anilinium 2-carboxy-4-nitrobenzoate salts: 4-X-C6H4NH3+·C8H4NO6− (X = H, Cl, Br and I)

Glidewell, C. — 2005-05-15

Anilinium 2-carboxy-4-nitrobenzoate, C6H8N+·C8H4NO6−, (I), 4-chloroanilinium 2-carboxy-4-nitrobenzoate, C6H7ClN+·C8H4NO6−, (II), 4-bromoanilinium 2-carboxy-4-nitrobenzoate, C6H7BrN+·C8H4NO6−, (III), and 4-iodoanilinium 2-carboxy-4-nitrobenzoate, C6H7IN+·C8H4NO6−, (IV), are approximately isostructural. In each compound, the ions are linked into complex sheets by a combination of O—H⋯O and N—H⋯O hydrogen bonds. Within the sheets, two distinct one-dimensional substructures can be identified, viz. a chain of edge-fused R33(13) rings and a double helix of simple C22(9) chains. In (I) and (IV), the sheets are linked by a C—H⋯Onitro hydrogen bond and a two-centre C—I⋯Onitro interaction, respectively, but the corresponding C—Cl⋯O and C—Br⋯O contact distances in (II) and (III) are not significantly shorter than the sum of the van der Waals radii.

mer-Triiodotripyridineindium(III)

Pardoe, J.A.J. — 2005-04-15

Crystals of the title compound, [InI3(C5H5N)3], consist of discrete molecules lying on a twofold axis running parallel to the crystallographic b axis. The molecules exhibit meridional octahedral stereochemistry, with In—I bond lengths of 2.8390 (6) and 2.8676 (3) Å, and In—N bond lengths of 2.323 (5) and 2.309 (4) Å.

Di-μ-halogeno-bis[halogeno(triphenylphosphine)mercury(II)], [Ph3PHgX(μ-X)2XHgPPh3], reinvestigated at 120 K for X = Cl and Br, and a second polymorph for X = I, also at 120 K

Mariyatra, M.B. — 2005-04-15

Di-μ-chloro-bis[chloro(triphenylphosphine)mercury(II)], [Hg2Cl4(C18H15P)2], (I), and di-μ-bromo-bis[bromo(triphenylphosphine)mercury(II)], [Hg2Br4(C18H15P)2], (II), have been reinvestigated at 120 K. The molecules of (I) lie across inversion centres in space group P21/n, and in both (I) and (II) the complexes are linked into three-dimensional frameworks by a combination of C—H⋯X (X = Cl and Br) and C—H⋯π(arene) hydrogen bonds. At 120 K, di-μ-iodo-bis[iodo(triphenylphosphine)mercury(II)], [Hg2I4(C18H15P)2], (III), crystallizes as a new polymorphic form having Z′ = {1\over 2}, where the complexes lie across inversion centres in space group P21/n; the complexes are linked into sheets by a combination of C—H⋯I and C—H⋯π(arene) hydrogen bonds. In the Z′ = 1 polymorph of this compound, a single C—H⋯I hydrogen bond generates simple chains.

3-Iodoanilinium 2-carboxy-6-nitrobenzoate: a three-dimensional framework built from O—H⋯O and N—H⋯O hydrogen bonds and a two-centre iodo–nitro interaction

Glidewell, C. — 2005-04-15

In the title compound, C6H7IN+·C8H4NO6−, the anions are linked by a single type of O—H⋯O hydrogen bond into C(7) chains, and these chains are linked via three independent N—H⋯O hydrogen bonds into sheets. The sheets, in turn, are linked by a two-centre iodo–nitro interaction into a single three-dimensional framework.

(η5-Cyclopentadienyl)(N,N-dimethyldithiocarbamato-κ2S,S′)[η4-tetrakis(trifluoromethyl)cyclobutadienyl]molybdenum(IV)

Davidson, J.L. — 2005-04-15

The title complex, [Mo(C8F12)(C5H5)(C3H6NS2)], contains both a η4-C4(CF3)4 cyclobutadienyl ligand with approximate C4v local symmetry and a η5-C5H5 cyclopentadienyl ring. The centroids of the rings and the S atoms of a chelating dithiocarbamate ligand define the pseudo-tetrahedral coordination of the Mo atom. The Mo—C(cyclobutadienyl) bond lengths [2.189 (2)–2.211 (2) Å] are unusually short, probably reflecting strong electron withdrawal by the trifluoromethyl groups. The molecules straddle crystallographic mirror planes.

Three isomeric N-(nitrophenyl)succinimides: isolated molecules, hydrogen-bonded sheets and a hydrogen-bonded three-dimensional framework

Glidewell, C. — 2005-04-15

Molecules of N-(2-nitrophenyl)succinimide, C10H8N2O4, are linked into sheets by a combination of C—H⋯O and C—H⋯π(arene) hydrogen bonds. Molecules of N-(3-nitrophenyl)succinimide are linked into a three-dimensional framework by a combination of a two-centre C—H⋯O hydrogen bond and a three-centre C—H⋯(O)2 hydrogen bond. Molecules of N-(4-nitrophenyl)succinimide which lie across twofold rotation axes in space group C2/c, participate in no direction-specific intermolecular interactions.

Chains of edge-fused hydrogen-bonded R33(12) rings in N-phenyl-4-nitrophthalimide

Glidewell, C. — 2005-04-15

Molecules of the title compound [systematic name: 5-nitro-1H-isoindole-1,3(2H)-dione], C14H8N2O4, adopt a conformation in the solid state which renders them chiral, and they are linked by three distinct types of direction-specific intermolecular interaction. The molecules are linked by two C—H⋯O hydrogen bonds [H⋯O = 2.50 and 2.52 Å, C⋯O = 3.118 (7) and 3.294 (7) Å, and C—H⋯O = 123 and 139°] into chains of edge-fused R_{3}^{3}(12) rings, which are themselves weakly linked into sheets by a combination of an aromatic π–π stacking interaction and a sheared-parallel carbonyl–carbonyl interaction.

21-Deoxycortisone (17α-hydroxy-4-pregnene-3,11,20-trione)

Dey, R. — 2005-04-15

The title compound, C21H28O4, a synthetic glucocorticoid, crystallizes with a single molecule in the asymmetric unit. Ring A is almost in a half-chair conformation, rings B and C are almost in chair conformations, and ring D is between a twist and a 13β-envelope conformation. The A/B ring junction is quasi-trans, whereas the B/C and C/D ring junctions both approach trans characteristics. The molecule as a whole is slightly convex towards the β side, with an angle of 9.60 (2)° between the C10—C19 and C13—C18 vectors. Molecular-packing and hydrogen-bonding (both intra- and intermolecular) interactions play a major role in the structural association of the compound.

Supramolecular structures of three isomeric 2-chloro-N-(nitrophenyl)nicotinamides

Souza, M.V.N. de — 2005-04-15

Molecules of 2-chloro-N-(2-nitrophenyl)nicotinamide, C12H8ClN3O3, are linked by two C—H⋯O hydrogen bonds into a chain of edge-fused R_{2}^{2}(14) and R_{4}^{4}(24) rings. In 2-chloro-N-(3-nitrophenyl)nicotinamide monohydrate, C12H8ClN3O3·H2O, the molecules are linked by a combination of N—H⋯O, O—H⋯O and O—H⋯N hydrogen bonds into a chain of edge-fused rings containing two distinct types of R_{4}^{4}(16) ring. In 2-chloro-N-(4-nitrophenyl)nicotinamide, C12H8ClN3O3, which crystallizes with Z′ = 2 in space group P21/n, the molecules are linked by two N—H⋯N hydrogen bonds into simple C_{2}^{2}(12) chains.

4-Nitrophenyl phenyl ether: sheets built from C—H⋯O and C—H⋯π(arene) hydrogen bonds

Glidewell, C. — 2005-03-15

In the title compound, C12H9NO3, the ether C—O—C angle is 119.65 (10)°. The molecules are linked into sheets by a combination of C—H⋯O and C—H⋯π(arene) hydrogen bonds, reinforced by an aromatic π–π stacking interaction.

Bis(tetra-n-butylammonium) and bis(tetraphenylphosphonium) salts of tris(2-oxo-1,3-dithiole-4,5-dithiolato)stannate(IV), both at 120 K

Comerlato, N.M. — 2005-03-15

The title compounds, (C16H36N)2[Sn(C3OS4)3], (I), and (C24H20P)2[Sn(C3OS4)3], (II), are examples of complex salts of the general form [Q]2[Sn(dmio)3], where Q is nBu4N+ or Ph4P+ and dmio is the 2-oxo-1,3-dithiole-4,5-dithiolate dianion. Features of both structures are the slightly distorted octahedral coordination of tin in the propeller-shaped dianions and the absence of any significant inter-anion contacts. The structure of (I) is particularly notable because all of the dianions in the sample crystal have the same propeller configuration, which is very unusual in this type of structure.

2-Iodo-6-methoxy-4-nitroaniline: tripartite ribbons built from N—H⋯O hydrogen bonds and iodo–nitro interactions are π-stacked into sheets

Garden, S.J. — 2005-03-15

Molecules of the title compound, C7H7IN2O3, are linked by pairs of N—H⋯O hydrogen bonds into C(8)C(8)[R_{2}^{2}(6)] chains of rings, and antiparallel pairs of such chains are linked by a two-centre iodo–nitro interaction into tripartite ribbons. A single aromatic π–π stacking interaction links the ribbons into sheets.

4′-Octyloxybiphenyl-4-carbonitrile polymorph III

Davey, R.J. — 2005-03-15

The title compound, C21H25NO, is a member of a well known family of liquid crystals (4-oxy-4′-cyanobiphenyls, OCBs) and packs in lamellar-type bilayers in the solid state, through CN⋯H hydrogen bonds. This packing type is analogous to that found of other members of the n-OCB homologous series, viz. 7-OCB and 9-OCB.

Polymorphism in ammonium 2,4,6-trimethylbenzenesulfonate

Aucott, S.M. — 2005-03-15

During investigations into sulfide- and selenide-amination reactions using the aminating agent o-mesitylsulfonylhydroxylamine, the monoclinic, (I), and orthorhombic, (II), polymorphs of ammonium 2,4,6-trimethylbenzenesulfonate, NH4+·C9H11O3S−, have been crystallized. Investigation of the hydrogen-bonding motifs within the two polymorphs shows that both contain N+—H⋯O− hydrogen bonds between the ammonium cations and the 2,4,6-trimethylbenzenesulfonate anions. Polymorph (I) contains R_{4}^{4}(12) and R_{4}^{2}(8) graph-set ring motifs, while polymorph (II) contains the same R_{4}^{4}(12) ring motif in combination with an R_{4}^{3}(10) motif. The two hydrogen-bonding patterns result in slightly different packing structures for the two polymorphs, but both are based on a thick-sheet arrangement, in which the NH4+ cations are enveloped between two layers of 2,4,6-trimethylbenzenesulfonate anions. In (I), the aromatic rings of the anions are approximately coplanar, giving parallel sheets, whereas in (II) the sheets are antiparallel and the anions pack in a herring-bone manner within the sheets, with angles of 78.76 (8)° between the planes of the aromatic rings.

Diphenylmercury, redetermined at 120 K: sheets built from a single C—H⋯π(arene) hydrogen bond

Glidewell, C. — 2005-02-15

At 120 K, the molecules of the title compound, [Hg(C6H5)2], lie across centres of inversion in space group P21/n and are linked by a single C—H⋯π(arene) hydrogen bond into (101) sheets. The same supramolecular structure is found at 298 K.

Piperazine-2,5-dione–oxalic acid–water (1/1/2) and a redetermination of piperazine-2,5-dione, both at 120 K: hydrogen-bonded sheets containing multiple ring types

Sarangarajan, T.R. — 2005-02-15

In piperazine-2,5-dione–oxalic acid–water (1/1/2), C4H6N2O2·C2H2O4·2H2O, both organic components lie across inversion centres in space group P\overline{1}. The molecules are linked by N—H⋯O and by both two-centre O—H⋯O and three-centre O—H⋯(O)2 hydrogen bonds into sheets built from R_{1}^{2}(5), R_{2}^{2}(8), R_{4}^{4}(8) and R_{5}^{4}(15) rings. In piperazine-2,5-dione, C4H6N2O2, where the molecules lie across centres of inversion in space group P21/c, the molecules are linked by paired N—H⋯O hydrogen bonds into ribbons of centrosymmetric R_{2}^{2}(8) rings, which are further linked into sheets by C—H⋯O hydrogen bonds, generating R_{4}^{3}(14) rings between the ribbons.

[(1R,2R)-2-Amino-1,2-diphenyl-N-(p-tolylsulfonyl)ethylamido]chloro(η6-ethoxybenzene)ruthenium(II) methanol solvate

Soleimannejad, J. — 2005-03-15

The title compound, [Ru(C21H21N2O2S)Cl(C8H10O)]·CH4O or [Ru(TsDPEN)Cl(η6-C6H5OCH2CH3)]·CH4O [where TsDPEN is (1R,2R)-1,2-diphenyl-N-(p-toluenesulfonyl)ethylenediamine], contains an S-chiral Ru centre in a distorted octahedral environment, with similar bond lengths and angles to analogous complexes. The very short (N—)H⋯Cl distance of 2.61 Å is ascribed to an intramolecular hydrogen bond.

N-(Diphenylselenio)diphenylsulfimidium tetraphenylborate

Aucott, S.M. — 2005-02-15

The title compound, C24H20NSSe+·C24H20B−, exhibits disorder (S/Se scrambling) of the chalcogen sites within the S—N—Se triad. Similar disorder was observed in the bromide salt [Aucott, Bailey, Elsegood, Gilby, Holmes, Kelly, Papageorgiou & Pedrón-Haba (2004). New J. Chem. pp. 959–966]. The S—N and Se—N bond lengths are 1.6735 (15) and 1.8045 (14) Å, respectively. Whereas the chalcogens in the bromide salt are involved in S⋯Br and Se⋯Br interactions of very similar distances, the scrambled S and Se sites in the title compound are involved in distinct non-bonded interactions. The site predominantly occupied by sulfur is involved in C—H⋯S/Se interactions, while the site predominantly occupied by selenium is involved in Se/S⋯π interactions.

Tris[4-(4-nitrophenyl)-3-aza-3-butenyl]amine: π-stacked chains of hydrogen-bonded R_{\bf 2}^{\bf 2}(26) dimers

Glidewell, C. — 2005-02-15

In the title compound {alternative name: N′-(4-nitrobenzylidene)-N,N-bis[2-(4-nitrobenzylideneamino)ethyl]-1,2-ethanediamine}, C27H27N7O6, the three independent NCH2CH2N=CHC6H4NO2 fragments all exhibit different conformations, resulting from the different direction-specific intra- and intermolecular interactions experienced. The molecules are linked by a single C—H⋯O hydrogen bond into centrosymmetric R_2^2(26) dimers, which are linked by π–π stacking interactions into [111] chains and, more weakly, into (01\overline 1) sheets.

trans-Di-μ-bromo-bis[bromo(triethylphosphine-κP)platinum(II)]

Cornet, S.M.M. — 2005-02-15

The title compound, [Pt2Br4(C6H15P)2], is a centrosymmetric dinuclear platinum(II) complex consisting of two square-planar platinum centres connected by two bridging Br atoms.

Tetra-n-butylammonium bromide–water (1/38)

Shimada, W. — 2005-02-15

Tetra-n-butylammonium bromide forms the title semi-clathrate hydrate crystal, C16H36N+·Br−·38H2O, under atmospheric pressure. The cation and anion lie at sites with mm symmetry and seven water molecules lie at sites with m symmetry in space group Pmma. Br− anions construct a cage structure with the water molecules. Tetra-n-butylammonium cations are disordered and are located at the centre of four cages, viz. two tetrakaidecahedra and two pentakaidecahedra in ideal cage structures, while all the dodecahedral cages are empty.

3,3-Difluoro-5-nitro-1H-indol-2(3H)-one: sheets of R22(8) and R46(34) rings built from three-centre N—H⋯(O)2 hydrogen bonds

Glidewell, C. — 2005-01-15

The title compound, C8H4F2N2O3, crystallizes with Z′ = 2 in the space group P21/c. The molecules are linked into sheets of R_{2}^{2}(8) and R_{4}^{6}(34) rings by two independent asymmetric three-centre N—H⋯(O)2 hydrogen bonds [H⋯O = 2.15/2.57 Å in one system and 2.23/2.46 Å in the other; N⋯O = 2.8959 (17)/3.2972 (16) and 2.9561 (16)/3.1774 (15) Å; N—H⋯O = 142/140 and 140/139°; O⋯H⋯O = 77 and 79°].

π-Stacked hydrogen-bonded sheets in N,N′-bis(4-nitrobenzylidene)ethane-1,2-diamine and π-stacked hydrogen-bonded chains in N,N′-bis(4-nitrobenzylidene)propane-1,3-diamine

Bomfim, J.A.S. — 2005-01-15

Molecules of N,N′-bis(4-nitrobenzylidene)ethane-1,2-diamine, C16H14N4O4, (I), lie across centres of inversion in space group P21/n and are linked into (10\overline 1) sheets by a single C—H⋯O hydrogen bond [H⋯O = 2.40 Å, C⋯O = 3.2166 (13) Å and C—H⋯O = 146°]; these sheets are linked into a three-dimensional array by a single aromatic π–π stacking interaction. Molecules of N,N′-bis(4-nitrobenzylidene)propane-1,3-diamine, C17H16N4O4, (II), lie across twofold rotation axes in space group C2/c and are linked into chains of spiro-fused rings by a single C—H⋯O hydrogen bond [H⋯O = 2.54 Å, C⋯O = 3.267 (2) Å and C—H⋯O = 130°]; these chains are linked into sheets by a single aromatic π–π stacking interaction.

Bis[(diphenylsulfimido)triphenylphosphonium] di-μ-bromo-bis[dibromopalladate(II)]

Dale, S.H. — 2005-01-15

The title compound, (C30H25NPS)2[Pd2Br6] or (Ph3PNSPh2)2[Pd2Br6], was crystallized from the reaction of (Ph3PNSPh2)[BPh4] with (PPh4)2[Pd2Br6], giving a salt rather than the intended coordination complex [PdBr3(Ph3PNSPh2)]. The compound crystallizes in the non-centrosymmetric space group Cc with one complete formula unit in the asymmetric unit. One of the two independent cations is disordered. The geometry of the two cations is compared with that of the only previously crystallized example of this cation, viz. its [SbCl6]− salt [Reck et al. (1982). Chem. Ber. 115, 2981–2996]. The bond angles within the P—N—S triad in the two cations in the title compound are narrower than those observed in the literature example, while the S—N bond lengths are slightly longer in the title compound. The P—N bond length in the ordered cation shows excellent agreement with that determined by Reck and co-workers, but the P—N bond lengths are lengthened slightly in the disordered cation. Weak C—H⋯Br interactions create a three-dimensional network, with cations and anions alternating along the crystallographic c direction.

S-Ethyl N-(4-chlorobenzoyl)dithiocarbamate: sheets built from π-stacked hydrogen-bonded chains

Low, J.N. — 2005-01-15

Molecules of the title compound, C10H10ClNOS2, are linked into C(4) chains by an N—H⋯O hydrogen bond [H⋯O = 2.16 Å, N⋯O = 3.013 (3) Å and N—H⋯O = 176°], and the chains are linked into sheets by a centrosymmetric π–π stacking interaction.

The effect of hydrogen-bonding anions on the structure of metal–sulfimide complexes

Dale, S.H. — 2005-01-15

Investigations into the effects of the choice of anion on the hydrogen-bonding interactions between anions and metal–sulfimide cationic complexes have led to the study of three novel compounds. Hexakis(S,S-diphenylsulfimide)cobalt(II) diiodide S,S-diphenylsulfimide acetonitrile disolvate, [Co(C12H11NS)6]I2·C12H11NS·2C2H3N, crystallizes in the centrosymmetric space group P\overline 1 with Z = 2. Six diphenylsulfimide ligands coordinate to the cobalt centre through their N atoms. Two iodide counter-ions hydrogen bond to the cation through N—H⋯I interactions, with N⋯I distances in the range 3.7302 (19)–3.8461 (19) Å. One extra molecule of sulfimide is included in the asymmetric unit, regardless of the metal–ligand ratio used in the synthesis, and this sulfimide molecule also hydrogen bonds to one of the iodide counter-ions through one N—H⋯I hydrogen bond. The reaction of FeCl3·6H2O with S,S-diphenylsulfimide monohydrate yields hexakis(S,S-diphenylsulfimide)iron(III) trichloride, [Fe(C12H11NS)6]Cl3. The complex crystallizes in the centrosymmetric cubic space group Pa\overline 3 and the asymmetric unit contains one-sixth of a formula unit. Two of the chloride anions each hydrogen bond to three sulfimide NH groups on opposite sides of the [Fe(Ph2SNH)6]3+ cation. The third chloride anion does not take part in any strong hydrogen bonding; instead it is surrounded by aromatic groups and is involved in C—H⋯Cl hydrogen bonds. The reaction of [Pt(Ph2SNH)4]Cl2 with I2 facilitates oxidation of the PtII metal centre to PtIV, producing tetrakis(S,S-diphenylsulfimide)diiodoplatinum(IV) dichloride dichloromethane disolvate, [PtI2(C12H11NS)4]Cl2·2CH2Cl2. The crystal structure is centrosymmetric, with the elongated octahedral cationic complex situated on an inversion centre. The chloride anions are hydrogen bonded to the cation through N—H⋯Cl hydrogen bonds, with two cis NH groups hydrogen bonded to each anion. Strong hydrogen bonding within these three compounds is limited to N—H⋯halide hydrogen bonds between the cation and two anions, with a three-up/three-down arrangement of the NH groups in the first two compounds. The anions also `cap' the NH groups in the third compound. In all three cases, the anions are also involved in weaker hydrogen bonds utilizing the plethora of relatively acidic aryl CH groups in the structures.

5-(1-Hydroxyethylidene)-1,3-dimethylpyrimidine-2,4,6(1H,3H,5H)-trione and four amino derivatives

Silva, E.T. da — 2005-01-15

In the structures of 5-(1-hydroxyethylidene)-1,3-dimethylpyrimidine-2,4,6(1H,3H,5H)-trione, C8H10N2O4, (I), 1,3-dimethyl-5-[1-(propylamino)ethylidene]pyrimidine-2,4,6(1H,3H,5H)-trione, C11H17N3O3, (II), and 5-[1-(2,2-dimethoxyethylamino)ethylidene]-1,3-dimethylpyrimidine-2,4,6(1H,3H,5H)-trione, C12H19N3O5, (III), there are no direction-specific intermolecular interactions. The molecules in 5-[1-(benzylamino)ethylidene]-1,3-dimethylpyrimidine-2,4,6(1H,3H,5H)-trione, C15H17N3O3, (IV), are linked into chains of edge-fused rings by a combination of one C—H⋯O hydrogen bond and one C—H⋯π(arene) hydrogen bond, while the molecules in 5-(1-hydrazinoethylidene)-1,3-dimethylpyrimidine-2,4,6(1H,3H,5H)-trione, C8H12N4O3, (V), are linked into a continuous framework structure by three distinct N—H⋯O hydrogen bonds, each involving a different O-atom acceptor. Each of compounds (I)–(V) contains an intramolecular hydrogen bond, of the O—H⋯O type in (I) and of the N—H⋯O type in (II)–(V).

Hydrogen-bonded sheets in (E)-2-nitrobenzaldehyde 4-nitrophenylhydrazone and a hydrogen-bonded framework structure in (E)-4-nitrobenzaldehyde 4-nitrophenylhydrazone

Wardell, J.L. — 2005-01-15

Molecules of (E)-2-nitrobenzaldehyde 4-nitrophenylhydrazone, C13H10N4O4, exhibit a strongly polarized molecular–electronic structure. The molecules are linked into sheets of some complexity, where pairs of hydrogen bonds act co-operatively to generate two independent substructures, each in the form of a chain of rings. In the isomeric compound (E)-4-nitrobenzaldehyde 4-nitrophenylhydrazone, the molecules exhibit orientational disorder; an extensive series of hydrogen bonds links the molecules into a continuous three-dimensional framework, whose formation is independent of the disorder.

β-[H2N(CH2)2NH2]0.5[ZnHPO3], a second modification of ethylenediamine zinc hydrogen phosphite

Gordon, L.E. — 2004-12-15

The title compound, poly[dizinc(II)-μ-ethylenediamine-di-μ-(hydrogen phosphito)], β-[H2N(CH2)2NH2]0.5[ZnHPO3] or [Zn2(HPO3)2(C2H8N2)]n, is a hybrid organic/inorganic solid built up from ethylenediamine molecules (which lie about inversion centres), Zn2+ cations (coordinated by three O atoms and one N atom) and HPO32− hydrogen phosphite groups. The organic species bond to the Zn atom as unprotonated ligands, acting as bridges between infinite ZnHPO3 layers that propagate as very buckled (001) sheets. The zincophosphite sheets contain polyhedral four- and eight-membered rings in a 4.82 topology. β-[H2N(CH2)2NH2]0.5·ZnHPO3 complements the previously described α modification of the same stoichiometry [Rodgers & Harrison (2000). Chem. Commun. pp. 2385–2386].

Bis(tetra-n-butylammonium) (μ-N,N′-diselenium dinitride)bis[tribromopalladate(II)]

Aucott, S.M. — 2004-12-15

The reaction of Se4N4 with (Bu4N)2[Pd2Br6] gives the title compound, (C16H36N)2[Pd2Br6(N2Se2)], in good yield. The [Pd2(Se2N2)Br6]2− anion lies on an inversion centre, and therefore the asymmetric unit contains half a formula unit. The crystal structure confirms the coordination of the Se2N2 unit to Pd through the N atoms, as previously assigned by IR spectroscopic analysis [Kelly, Slawin & Soriano-Rama (1997). J. Chem. Soc. Dalton Trans. pp. 559–562]. The title compound contains the longest Pd—N bond so far observed for such systems.

Sodium 1-carboxycyclopropane-1-carboxylate cyclopropane-1,1-dicarboxylic acid monohydrate

Muir, K.W. — 2004-12-15

In the title type B2 acid salt, Na(LH)(LH2)·H2O [LH2 = C2H4C(CO2H)2] or Na+·C5H5O4−·C5H6O4·H2O, the vertices of a distorted octahedron centred on each Na+ cation are defined by six O atoms, one from a water molecule, one from an internally hydrogen-bonded LH− anion and four from three neutral LH2 acid molecules. Chains of edge-sharing O6 octahedra are stabilized by hydrogen bonds, which interconnect the donor H2O and LH2 molecules and LH− anions. In particular, the LH2 molecule donates H atoms to LH− and H2O and forgoes the internal hydrogen bond which stabilizes the free acid and all of its characterized salts.

11-Methyl-2,3-benzodipyrrin-1-one

Bonnett, R. — 2004-12-15

The title compound {alternative names: 11-methyl-2,3-benzopyrromethenone and 3-[(1-methylpyrrol-2-yl)methylidene]-2,3-dihydro-1H-isoindol-1-one}, C14H12N2O, was prepared by the base-catalysed condensation of phthalimidine with 2-formyl-1-methylpyrrole; yellow orthorhombic crystals, space group Pbca, were obtained from ethanol. The molecule is almost planar, having Z(−)antiperiplanar geometry. The molecules are arranged in pairs with intermolecular hydrogen bonding between lactam functions. Comparison with literature values for polyalkyldipyrrin-1-ones shows that, apart from the local constraints of the benzene ring, the fused benzo ring has little effect on the molecular dimensions of the dipyrrin-1-one skeleton.

The copper(II) complexes di-μ-bromo-bis{[2,6-bis(pyrazol-1-yl)pyridine]perchloratocopper(II)} and [2,6-bis(pyrazol-1-yl)pyridine]dibromocopper(II)

Chakrabarty, S. — 2004-12-15

The two title compounds, di-μ-bromo-bis{[2,6-bis(pyrazol-1-yl-κN2)pyridine-κN](perchlorato-κO)copper(II)}, [Cu2Br2(ClO4)2(C11H9N5)2], (I), and [2,6-bis(pyrazol-1-yl)pyridine]dibromocopper(II), [CuBr2(C11H9N5)], (II), were synthesized by only slight modifications of the same reaction; compound (II) was formed by adding one molar equivalent of pyrazole (C3N2H4) to the reaction mixture of (I). Compound (I) is a bromo-bridged dinuclear copper(II) compound stabilized by weak interactions with the perchlorate anions (ClO4−), while (II) is a related mononuclear species, which has a distorted square-pyramidal geometry.

Isomeric nitrophthalimides: sheets built from N—H⋯O and C—H⋯O hydrogen bonds

Glidewell, C. — 2004-12-15

Molecules of 3-nitrophthalimide, C8H4N2O4, are linked into sheets by a combination of one N—H⋯O hydrogen bond [H⋯O = 1.99 Å, N⋯O = 2.8043 (14) Å and N—H⋯O = 176°] and two independent C—H⋯O hydrogen bonds [H⋯O = 2.36 and 2.56 Å, C⋯O = 3.1639 (16) and 3.4386 (16) Å, and C—H⋯O = 142 and 153°], and these sheets are linked into pairs by a single π–π stacking interaction. Molecules of isomeric 4-nitrophthalimide are linked into sheets by a combination of one three-centre N—H⋯(O)2 hydrogen bond [H⋯O = 2.14 and 2.55 Å, N⋯O = 2.974 (3) and 3.231 (3) Å, N—H⋯O = 151 and 131°, and O⋯H⋯O = 76°] and two independent two-centre C—H⋯O hydrogen bonds [H⋯O = 2.38 and 2.54 Å, C⋯O = 3.257 (4) and 3.452 (4) Å, and C—H⋯O = 156 and 168°].

Butane-1,4-diamine zinc(II) hydrogen phosphite

Ritchie, L.K. — 2004-12-15

The title compound, poly[zinc(II)-μ-butane-1,4-diamine-μ-(hydrogen phosphito)] (C4H12N2)0.5[ZnHPO3], is a hybrid organic–inorganic solid built up from 1,4-diaminobutane molecules, Zn2+ cations (coordinated by three O atoms and one N atom) and HPO32− hydrogen phosphite groups. The organic species bonds to the Zn atom as an unprotonated ligand, resulting in it acting as a bridge between infinite ZnHPO3 layers, which propagate in (100). The complete butane-1,4-diamine species is generated from a H2N(CH2)2– half molecule by inversion symmetry. The zincophosphite sheets contain polyhedral four- and eight-membered rings in a 4.82 topology.

6-(4-Bromophenyl)-6,7-dihydro-1,3-dioxolo[4,5-g]quinolin-8(5H)-one: bilayers built from N—H⋯O, C—H⋯O and C—H⋯π(arene) hydrogen bonds

Low, J.N. — 2004-11-15

Molecules of the title compound, C16H12BrNO3, exhibit a polarized molecular–electronic structure. A combination of one N—H⋯O hydrogen bond and one C—H⋯O hydrogen bond links the molecules into sheets, and pairs of sheets are linked into bilayers by a single C—H⋯π(arene) hydrogen bond.

The 2:1 adducts of (benzoylmethylene)triphenylphosphorane with fumaric and terephthalic acids

Spencer, E.C. — 2004-11-15

Co-crystals of the ylide (benzoylmethylene)triphenylphosphorane (BPPY) with either fumaric acid, viz. (benzoylmethylene)triphenylphosphorane–fumaric acid (2/1), C26H21OP·0.5C4H4O4, or terephthalic acid, viz. (benzoylmethylene)triphenylphosphorane–terephthalic acid (2/1), C26H21OP·0.5C8H6O4, have a stoichiometric ratio of 2:1 between the ylide and the corresponding dicarboxylic acid. In both adducts, the acid component lies across a centre of inversion. In neither case is the ylide protonated by the organic acid; instead the H atoms of the non-ionized dicarboxylic acid molecules participate in the formation of strong O—H⋯O hydrogen bonds with the benzoyl O atom of the ylide species. These structures are the first reported examples of co-crystals containing non-protonated BPPY.

3-Phenyl-4H,6H-1,2,4-oxadiazol-5-one

Glidewell, C. — 2004-11-15

Molecules of the title compound, C9H8N2O2, are linked into complex sheets by a combination of N—H⋯O, C—H⋯N and C—H⋯O hydrogen bonds.

2-Acetamido-4-p-tolyl-1,3-thiazole and 2-amino-4-p-tolyl-1,3-thiazolium chloride dihydrate

Lynch, D.E. — 2004-11-15

The structures of 2-acetamido-4-tolyl-1,3-thiazole, C12H12N2OS, (I), and 2-amino-4-tolyl-1,3-thiazolium chloride dihydrate, C10H11N2S+·Cl−·2H2O, (II), reveal that both molecules are essentially planar, with the respective dihedral angles between the benzene and thiazole rings being 2.9 (1) and 10.39 (7)°. Compound (I) associates via a single N—H⋯O interaction to form a flat alternate-facing hydrogen-bonded chain [graph-set C{_2^2}(4)]. Compound (II) packs with the hydrogen-bonding associations of the Cl atoms and the water molecules creating a convoluted hydrogen-bonded ribbon made up of five-membered donor–acceptor rings, involving three water O atoms (with associated H atoms) and two Cl atoms. The thiazolium rings form stacked columns, aligned in the same direction as the hydrogen-bonded ribbons, of alternate-facing molecules that are also involved in the hydrogen-bonding network, linking to the Cl atoms and one of the water molecules. Subsequently, each Cl atom is the hydrogen-bond acceptor for five separate O/N—H associations.

N-(3-Methyl-4-oxo-3,4-dihydropteridin-2-yl)glycine: hydrogen-bonded sheets of R44(22) and R44(30) rings

Arranz Mascarós, P. — 2004-11-15

Molecules of the title compound, C9H9N5O3, are linked into sheets by a combination of one O—H⋯N hydrogen bond and one N—H⋯O hydrogen bond.

5,5′-Di-tert-butyl-2,2′-dihydroxy-3,3′-methanediyldibenzaldehyde and its allyl-protected dialcohol and dialdehyde precursors

Goetz, S. — 2004-11-15

5,5′-Di-tert-butyl-2,2′-dihydroxy-3,3′-methanediyldibenzaldehyde, C23H28O4, (IV), has been structurally characterized in two polymorphic forms. The tetragonal form, (in I41/a) has been reported previously but is redetermined and reinterpreted here, while the monoclinic form, (in C2/c) is reported for the first time. In both polymorphs, the molecule lies on a crystallographic twofold axis. Two precursors in the synthesis of (IV), namely 2,2′-bis(allyloxy)-5,5′-di-tert-butyl-3,3′-methanediyldibenzenemethanol (C29H40O4) and 2,2′-bis(allyloxy)-5,5′-di-tert-butyl-3,3′-methanediyldibenzaldehyde (C29H36O4) have also been characterized.

Hydrogen-bonded chains in 5-methyl-2-trifluoromethyl-1,2,4-triazolo[1,5-a]pyrimidin-7(4H)-one and hydrogen-bonded chains of rings in 5-amino-3-trifluoromethyl-1H-1,2,4-triazole–5-methyl-2-trifluoromethyl-1,2,4-triazolo[1,5-a]pyrimidin-7(4H)-one (1/1), the co-crystal of a reaction product and one of its precursors

Boechat, N. — 2004-10-15

In the title compounds, C7H5F3N4O, (I), and C3H3F3N4·C7H5F3N4O, (II), all of the molecular components exhibit some polarization of their molecular–electronic structures. The molecules in (I) are linked into simple C(6) chains, while in (II), the components are linked by a combination of two-centre N—H⋯N and N—H⋯O, and three-centre N—H⋯(O,N) hydrogen bonds into chains containing R{_1^2}(5), R{_2^1}(6) and R{_2^2}(8) rings.

Polarized molecular–electronic structures and supramolecular aggregation in 1-(6-amino-1,3-benzodioxol-5-yl)-3-arylprop-2-en-1-ones

Low, J.N. — 2004-10-15

Molecules of 1-(6-amino-1,3-benzodioxol-5-yl)-3-(4-methylphenyl)prop-2-en-1-one, C17H15NO3, (I), 1-(6-amino-1,3-benzodioxol-5-yl)-3-(4-methoxyphenyl)prop-2-en-1-one, C17H15NO4, (II), and 1-(6-amino-1,3-benzodioxol-5-yl)-3-[4-(trifluoromethyl)phenyl]prop-2-en-1-one, C17H12F3NO3, (III), all contain an intramolecular N—H⋯O hydrogen bond and all exhibit polarized molecular–electronic structures. The molecules of (I) are linked into simple sheets, generated by translation, by means of one N—H⋯O and one C—H⋯π(arene) hydrogen bond. Compound (II) crystallizes as two concomitant polymorphs, viz. (IIa), with Z′ = 1 in P21/c, and (IIb), with Z′ = 2 in P\overline 1. In (IIa), intra- and intermolecular N—H⋯O hydrogen bonds generate a helical chain of rings, and these chains are linked into sheets by simple helical chains built from a C—H⋯π(arene) hydrogen bond, while in (IIb), the molecules are linked into simple chains by a C—H⋯O hydrogen bond. In (III), where Z′ = 2, each type of molecule forms a simple N—H⋯O hydrogen-bonded chain generated by translation and the two types of chain are linked by a single π–π stacking interaction.

Hydrogen-bonded dimers in 2-nitrobenzaldehyde hydrazone and a three-dimensional hydrogen-bonded framework in 3-nitrobenzaldehyde hydrazone

Glidewell, C. — 2004-09-15

Molecules of 2-nitrobenzaldehyde hydrazone, C7H7N3O2, where Z′ = 2, are linked by two N—H⋯N hydrogen bonds into isolated dimers, whereas in the isomeric 3-nitrobenzaldehyde hydrazone, where Z′ = 1, the molecules are linked by one N—H⋯O hydrogen bond and one N—H⋯N hydrogen bond into a three-dimensional framework structure.

Hydantoin and hydrogen-bonding patterns in hydantoin derivatives

Yu, F.-L. — 2004-10-15

The structure of hydantoin (imidazolidine-2,4-dione), C3H4N2O2, has been determined from a twinned crystal. The two carbonyl bond lengths are nearly equal, even though one of them adjoins electron-donating NH groups to either side while the other is adjacent to only one. Ab initio molecular-orbital calculations yield more negative Löwdin charge on the former than the latter. Hydantoin molecules form two chains linked by N—H⋯O hydrogen bonds, from which inversion centres create a `chain of rings'. Out of 50 hydantoin moieties in 49 independent molecules of hydantoin derivatives in the Cambridge Structural Database [Version 5.25; Allen (2002). Acta Cryst. B58, 380–388], five show this arrangement, six are a variant using the same O atom twice, five form a chain of edge-fused 12-membered hydrogen-bonded rings, and all but three of the remainder have one eight-membered ring and/or one chain connecting their hydantoin rings.

Transition metal complexes with pyrazole-based ligands. XIX. Diaquabis(3,5-dimethyl-1H-pyrazole-1-carboxamidine-κ2N,N′)metal(II) dinitrate, with metal = Co and Ni

Jaćimović, Ž.K. — 2004-10-15

The two title isostructural and isomorphous complexes, [M(C6H10N4)2(H2O)2](NO3)2 (M is Co or Ni), contain the transition metal in a distorted octahedral geometry, coordinated by four N atoms of two neutral bidentate organic ligands in the equatorial plane and two water O atoms molecules in the axial positions. The cation is centrosymmetric, with the transition metal located on an inversion centre. The structures are stabilized by a three-dimensional network of hydrogen bonding.

Orthorhombic and monoclinic polymorphs of 1,3,5-triphenylperhydro-1,3,5-triazine-2,4,6-trione at 120 K: chains and sheets formed by C—H⋯π(arene) hydrogen bonds

Mariyatra, M.B. — 2004-09-15

The title compound, C21H15N3O3, crystallizes in two polymorphic forms. In the orthorhombic polymorph, (I), in space group Fdd2 with Z′ = 1, the molecules lie in general positions, while in the monoclinic polymorph, (II), in space group C2/c with Z′ = {1 \over 2}, the molecules lie across twofold rotation axes. In each polymorph, the molecules are linked by a single C—H⋯π(arene) hydrogen bond, forming chains in polymorph (I) and sheets in (II).

Supramolecular structures of three configurational isomers of 1-phenylethanaminium malate(1–)

Turkington, D.E. — 2004-08-15

In rac-1-phenylethanaminium rac-malate(1−), C8H12N+·C4H5O5−, (I), the anions are linked by two inter-anion O—H⋯O hydrogen bonds into sheets generated by a glide plane and hence containing both enantiomers of the anion. The cations are linked to the anion sheets by three N—H⋯O hydrogen bonds, such that cations of R configuration are bonded to one face of the sheet and cations of S configuration are bonded to the other face. In (R)-1-phenylethanaminium (S)-malate(1−), C8H12N+·C4H5O5−, (III), the anions are again linked by two O—H⋯O hydrogen bonds, in one of which the H atom is disordered over two sites, into sheets very similar to those in (I) but which are generated in (III) by translation and so contain only a single enantiomer. The cations in (III) are linked to the anion sheets by three N—H⋯O hydrogen bonds, but the cations are bonded to only one face of the anion sheet. Co-crystallization of (R)-1-phenylethanamine with rac-malic acid gives the salt (R)-1-phenylethanaminium malate(1−) C8H12N+·C4H5O5−, (II), with a structure very similar to that of (III) but where only ca 75% of the anion sites are occupied by (S)-malate(1−), with the remaining 25% occupied by (R)-malate(1−). The layers in (II) show a significant displacement along the [001] direction compared with those in (III).

10-(4-Chlorophenyl)-7-methyl-5,6-dihydrobenzo[h]pyrazolo[5,1-b]quinazoline and 2-(4-chlorophenyl)-5-methyl-6,7-dihydrobenzo[h]pyrazolo[1,5-a]quinazoline: isomeric molecules linked into hydrogen-bonded dimers or π-stacked chains

Low, J.N. — 2004-08-15

The isomeric title compounds 10-(4-chlorophenyl)-7-methyl-5,6-dihydrobenzo[h]pyrazolo[5,1-b]quinazoline, (I), and 2-(4-chlorophenyl)-5-methyl-6,7-dihydrobenzo[h]pyrazolo[1,5-a]quinazoline, (II), both C21H16ClN3, exhibit peripheral delocalization in the heteroaromatic portion of the fused ring system. The molecules of (I) are linked into centrosymmetric dimers by a single C—H⋯π(arene) hydrogen bond, and the molecules of (II), where Z′ = 2, are linked by π–π stacking interactions into chains in which the two types of molecules alternate.

2-Amino-2-thiazoline and its 1:1 organic salt with 2-naphthoxyacetic acid

Lynch, D.E. — 2004-09-15

The crystal structures of 2-amino-2-thiazoline, C3H6N2S, and 2-amino-2-thiazolinium 2-naphthoxyacetate, C3H7N2S+·C12H9O3−, are reported. The structure of 2-amino-2-thiazoline consists of two unique molecules that construct a convoluted hydrogen-bonded ribbon involving R_2^2(8) graph-set association via both N—H⋯N and N—H⋯S interactions. The organic salt structure consists of the two molecules associated via an R_2^2(8) graph-set dimer through N—H⋯O interactions, with the hydrogen-bonding network propagated via additional N—H⋯O three-centre interactions from the second 2-amine H atom.

Ethyl 2-amino-4-tert-butyl-1,3-thiazole-5-carboxylate and 6-methylimidazo[2,1-b]thiazole–2-amino-1,3-thiazole (1/1)

Lynch, D.E. — 2004-08-15

The structure of ethyl 2-amino-4-tert-butyl-1,3-thiazole-5-carboxylate, C10H16N2O2S, (I), and the structure of the 1:1 adduct 6-methylimidazo[2,1-b]thiazole–2-amino-1,3-thiazole (1/1), C6H6N2S·C3H4N2S, (II), have been determined. The molecules in (I) associate via a hydrogen-bonded R{_2^2}(8) dimer consisting of N—H⋯N interactions, with the hydrogen-bonding array additionally involving N—H⋯O interactions to one of the carboxylate O atoms. The 2-aminothiazole molecules in (II) also associate via an N—H⋯N hydrogen-bonded R{_2^2}(8) dimer, with an additional N—H⋯N interaction to the Nsp2 atom of the imidazothiazole moiety, creating hydrogen-bonded quartets.

A compound of a novel tetraaza-macrocycle with trinuclear tetracyanonickelate-bridged cations

Curtis, N.F. — 2004-08-15

The cation of the title compound, [Cu(L)]2+, is formed by Michael condensation of (4,6,6-trimethyl-3,7-diazanon-3-ene-1,9-diamine)copper(II) with methanal and nitropropane. This cation forms a tetracyanonickelate(II) compound, the unit cell of which contains two centrosymmetric tetracyanonickelate(II)-bridged trinuclear cations, namely diaqua-1,3κ2O-di-μ-cyano-1:2κ2C:N;1:3κ2C:N-dicyano-1κ2C-bis(13-ethyl-5,7,7-trimethyl-13-nitro-1,4,8,11-tetraazacyclotetradec-4-ene)-2κ4N1,N4,N8,N11;3κ4N1,N4,N8,N11-dicopper(II)nickel(II) di-μ-cyano-1:2κ2C:N;1:3κ2C:N-dicyano-1κ2C-bis(13-ethyl-5,7,7-trimethyl-13-nitro-1,4,8,11-tetraazacyclotetradec-4-ene)-2κ4N1,N4,N8,N11;3κ4N1,N4,N8,N11-dicopper(II)nickel(II) bis[tetracyanonickelate(II)] octahydrate, [Cu2Ni(CN)4(C15H31N5O2)2(H2O)2][Cu2Ni(CN)4(C15H31N5O2)2][Ni(CN)4]2·8H2O. One cation, [(L)Cu–NC–Ni(CN)2–CN–Cu(L)]2+, has an axially coordinated bridging [Ni(CN)4]2− ion, with a Cu—N distance of 2.226 (3) Å and a Cu—N—C angle of 168.2 (3)°. The other cation, [(H2O)(L)Cu–NC–Ni(CN)2–CN–Cu(L)(OH2)]2+, has water axially coordinated trans to a weakly bound bridging [Ni(CN)4]2− ion, with a Cu—O distance of 2.396 (3) Å, a Cu—N distance of 2.677 (4) Å, an O—Cu—N angle of 168.7 (1)° and a Cu—N—C angle of 137.7 (3)°. These cations, plus independent [Ni(CN)4]2− ions and water molecules, are linked into a hydrogen-bonded network. All [Ni(CN)4]2− ions are on centres of symmetry.

Redetermination of triethylammonium chloride in the space group P31c

Churakov, A.V. — 2004-08-15

The structure of triethylammonium chloride, C6H16N+·Cl−, has been redetermined in the space group P31c. In contrast with previous refinements in the space group P63mc, no disorder of the triethylammonium cation was observed.

N-(4-Fluorophenyl)-4-nitrophthalimide: tripartite hydrogen-bonded sheets

Glidewell, C. — 2004-07-15

Molecules of the title compound, C14H7FN2O4, are linked by two C—H⋯O hydrogen bonds [H⋯O = 2.42 and 2.44 Å, C⋯O = 3.173 (9) and 3.313 (10) Å, and C—H⋯O = 134 and 157°] into deep tripartite sheets, where the central layer is built from hydrogen-bonded R{_6^6}(24) rings and where the F atoms all lie on the exterior surfaces of the sheets.

Partially oxidized {2-[(benzoylmethylene)diphenyl-λ5-phosphino]ethyl}diphenylphosphine as a monohydrate

Mohamed, E.M. — 2004-07-15

The title compound is a co-crystal of {2-[(benzoylmethylene)diphenyl-λ5-phosphino]ethyl}diphenylphosphine oxide, {2-[(benzoylmethylene)diphenyl-λ5-phosphino]ethyl}diphenylphosphine and water in an approximate 2:1:3 ratio, with an overall composition of C34H30O1.678P2·H2O. The ylidic portion shows the expected electronic polarization, and the organic components are linked by a combination of C—H⋯O and C—H⋯π(arene) hydrogen bonds.

S-Ethyl N-benzoyldithiocarbamate: two independent hydrogen-bonded R_{\bf 2}^{\bf 2}(8) dimers of different symmetry linked into chains by a C—H⋯π(arene) interaction

Low, J.N. — 2004-07-15

The title compound, C10H11NOS2, crystallizes with Z′ = 2 in space group C2/c. The molecules are linked by two N—H⋯S hydrogen bonds [H⋯S = 2.60 and 2.62 Å, N⋯S = 3.350 (2) and 3.490 (2) Å, and N—H⋯S = 143 and 172°] into two distinct types of R_2^2(8) dimer, viz. one generated by inversion and the other by a twofold rotation axis. A single C—H⋯π(arene) hydrogen bond links the two types of dimer into chains.

rac-3-(5-Amino-3-methyl-1-phenyl-1H-pyrazol-4-yl)-2-phenylthiazolidin-4-one: sheets built from N—H⋯N and C—H⋯π(arene) hydrogen bonds

Low, J.N. — 2004-07-15

The title compound, C19H18N4OS, crystallizes in space group P\overline 1 with Z′ = 2. The two molecules in the selected asymmetric unit are nearly enantiomorphous. The molecules are linked by two N—H⋯N hydrogen bonds [H⋯N both 2.20 Å, N⋯N = 3.064 (3) and 3.077 (3) Å, and N—H⋯N = 165 and 172°] into C{_2^2}(10) chains, and these chains are linked into sheets by two independent C—H⋯π(arene) hydrogen bonds.

3-tert-Butyl-7,7-dimethyl-1-phenyl-5,6,7,8-tetrahydroimidazo[3,4-b]quinolin-5-one and 2,8,8-trimethyl-5-phenyl-6,7,8,9-tetrahydroimidazo[2,3-a]quinolin-6-one: chains generated by C—H⋯N hydrogen bonds

Low, J.N. — 2004-07-15

In both 3-tert-butyl-7,7-dimethyl-1-phenyl-5,6,7,8-tetrahydroimidazo[3,4-b]quinolin-5-one, C22H25N3O, (I), and 2,8,8-trimethyl-5-phenyl-6,7,8,9-tetrahydroimidazo[2,3-a]quinolin-6-one, C19H19N3O, (II), the heterobicyclic portions of the molecules are planar, with naphthalene-type delocalization in (II), while the carbocyclic ring in each compound adopts an envelope conformation. In both (I) and (II), the molecules are linked weakly into chains by a single C—H⋯N hydrogen bond.

Hydrogen-bonding adducts of benzenepolycarboxylic acids with N,N-dimethylformamide: benzene-1,4-dicarboxylic acid N,N-dimethylformamide disolvate, benzene-1,2,4,5-tetracarboxylic acid N,N-dimethylformamide tetrasolvate and benzene-1,2,3-tricarboxylic acid N,N-dimethylformamide disolvate monohydrate

Dale, S.H. — 2004-06-15

The N,N-dimethylformamide (DMF) solvates of terephthalic acid, H2TA·2DMF (C8H6O6·2C3H7NO), pyromellitic acid, H4PMA·4DMF (C10H6O8·4C3H7NO), and hemimellitic acid, H3HMA·2DMF·H2O (C9H6O6·2C3H7NO·H2O), are reported. The DMF solvate of terephthalic acid is centrosymmetric, containing one complete formula unit in the asymmetric unit. Both carboxylic acid groups hydrogen bond to a DMF molecule via an R_2^2(7) O—H⋯O/C—H⋯O motif. Discrete H2TA·2DMF units are observed. The DMF solvate of pyromellitic acid is centrosymmetric and the asymmetric unit contains half a formula unit. One of the unique carboxylic acid groups forms an R_2^2(7) motif with a DMF molecule, while the other forms a linear O—H⋯O hydrogen bond to the second unique DMF molecule. Discrete H4PMA·4DMF units are observed. The DMF solvate of hemimellitic acid is non-centrosymmetric and includes a molecule of water per formula unit. Both DMF molecules form an R_2^2(7) motif with the two outer carboxylic acid groups of HMA. A one-dimensional ladder structure is formed via hydrogen bonding between the central carboxylic acid group and the water molecules. The carboxylic acid R_2^2(8) head-to-tail motif is not observed in any of these examples. The inclusion of DMF thereby has the effect of limiting the dimensionality of the structures.

Three hexahydropyridopyrimidine-spiro-cyclohexanetriones: supramolecular structures generated by O—H⋯O, N—H⋯O, C—H⋯O and C—H⋯π hydrogen bonds, and π–π stacking interactions

Low, J.N. — 2004-06-15

4′,4′-Dimethyl-2-methylsulfanyl-3,4,5,6,7,8-hexahydropyrido[2,3-d]pyrimidine-6-spiro-1′-cyclohexane-2′,4,6′-trione, C15H19N3O3S, (I), has a markedly polarized molecular–electronic structure, and the molecules are linked into a three-dimensional framework by a combination of N—H⋯O, C—H⋯O and C—H⋯π hydrogen bonds. 8-Hydroxymethyl-4′,4′-dimethyl-2-methylsulfanyl-3,4,5,6,7,8-hexahydropyrido[2,3-d]pyrimidine-6-spiro-1′-cyclohexane-2′,4,6′-trione, C16H21N3O4S, (II), where the hydroxymethyl substituent is disordered over two sets of sites, has a much less polarized structure than (I); the molecules are linked by a combination of O—H⋯O and N—H⋯O hydrogen bonds into chains containing alternating R_2^2(8) and R_2^2(16) rings, and these chains are linked into sheets by a combination of a π–π stacking interaction and a C—H⋯O hydrogen bond. 8-Ethoxymethyl-2-methoxy-4′,4′-dimethyl-3,4,5,6,7,8-hexahydropyrido[2,3-d]pyrimidine-6-spiro-1′-cyclohexane-2′,4,6′-trione, C18H25N3O5, (III), has an unpolarized electronic structure, and a combination of N—H⋯O, C—H⋯O and C—H⋯π hydrogen bonds links the molecules into sheets.

(4,4,12,12-Tetramethyl-5,8,11-triazapenta-2,14-dione 2-oxime 14-oximato-κ5N)copper(II) perchlorate: a copper(II) compound with a pentadentate triamine–oxime–oximate ligand

Curtis, N.F. — 2004-06-15

The title compound, [Cu(C16H34N5O2)]ClO4, has discrete square-pyramidal (triamine–oxime–oximato)copper(II) cations and perchlorate anions. The cations have very approximate mirror symmetry, with the oxime [Cu—N = 2.066 (2) Å], oximate [Cu—N = 2.087 (2) Å] and amine N atoms [Cu—N = 2.138 (2) and 2.095 (2) Å] in the tetrahedrally twisted basal plane, and the `central' amine N atom coordinated axially [Cu—N = 2.183 (2) Å]. The oxime and oximate groups are linked by an O—H⋯O hydrogen bond, forming a pseudo-cyclic pentadentate ligand, with an O⋯O distance of 2.395 (3) Å.

Molecular conformation and supramolecular aggregation in four 2,3,4,5-tetrahydro-3,4-diphenylbenzothiazepines

Muthukumar, M. — 2004-06-15

In (2RS,4RS)-1-acetyl-2,3,4,5-tetrahydro-2,4-diphenyl-1,5-benzothiazepine, C23H21NOS, (I), and (2RS,4RS)-1-chloroacetyl-2,3,4,5-tetrahydro-2,4-diphenyl-1,5-benzothiazepine,C23H20ClNOS, (II), the seven-membered rings have boat conformations, whereas in (2RS,4RS)-1-benzoyl-2,3,4,5-tetrahydro-2,4-diphenyl-1,5-benzothiazepine, C28H23NOS, (III), this ring has a conformation intermediate between the boat and twist-boat forms. The molecules of (I) are linked into isolated R_2^2(16) dimers by two C—H⋯O hydrogen bonds [H⋯O = 2.41 and 2.47 Å, C⋯O = 3.268 (3) and 3.336 (3) Å, and C—H⋯O = 150 and 152°]. In (II), the molecules are again linked by two C—H⋯O hydrogen bonds [H⋯O = 2.42 and 2.48 Å, C⋯O = 3.295 (3) and 3.364 (2) Å, and C—H⋯O = 153 and 154°], forming chains of alternating R_2^2(18) and R_2^2(22) rings. Two C—H⋯O hydrogen bonds [H⋯O = 2.49 and 2.53 Å, C⋯O = 3.347 (2) and 3.295 (2) Å, and C—H⋯O = 150 and 138°] link the molecules of (III) into sheets containing alternating R_2^2(22) and R_6^4(30) rings. Re-examination of the published structure of (2RS,4RS)-2,3,4,5-tetrahydro-2,4-diphenyl-1,5-benzothiazepine shows that the molecules are linked by three C—H⋯π(arene) hydrogen bonds into a three-dimensional framework.

The supramolecular structure of 6-hydroxy-1,3-benzoxathiol-2-one (tioxolone)

Byres, M. — 2004-06-15

The planar molecules of 6-hydroxy-1,3-benzoxathiol-2-one, C7H4O3S, are linked by extensive O—H⋯O and C—H⋯O hydrogen bonding and are further stablilized by face-to-face π–π interactions.

Diospyrin

Harrison, W.T.A. — 2004-06-15

The structure of the title natural product, 1′,5-dihydroxy-3′,7-dimethyl-2,2′-binaphthalene-1,4,5′,8′-tetrone, C22H14O6, confirms the atomic connectivity postulated on the basis of spectroscopic data. The geometric parameters are normal and the angle between the planes of the two ring systems is 59.74 (2)°. The crystal packing is influenced by O—H⋯O hydrogen bonds, and possible short C—H⋯O and π–π stacking interactions.

The catena-arsenite chain anion, [AsO2]nn−: (H3NCH2CH2NH3)0.5[AsO2] and NaAsO2 (revisited)

Lee, C. — 2004-05-15

The title compounds contain the catena-arsenite [AsO2]nn− unit, in which the AsIII atom is pyramidally coordinated to one terminal and two bridging O atoms, resulting in an infinite anionic chain. Ethylenediammonium catena-arsenite, (C2H10N2)0.5[AsO2], is the first example of this anion in the company of an organic cation. The ethylenediammonium species interact with the [AsO2]− chains by way of N—H⋯O hydrogen bonds. The structure of sodium catena-arsenite, Na[AsO2] [Menary (1958). Acta Cryst. 11, 742–743], has been redetermined to yield more reliable geometrical parameters. The As—O distances are normal and the Na+ cation is seven-coordinate [Na—O = 2.285 (4)–3.063 (4) Å] in a distorted capped trigonal prismatic geometry.

Monoclinic pseudosymmetry in 2-phenoxybenzenesulfonamide, a triclinic structure having Z′ = 4, and spontaneous resolution in monoclinic N-methyl-2-phenoxybenzenesulfonamide

Glidewell, C. — 2004-05-15

2-Phenoxybenzenesulfonamide, C12H11NO3S, (I), crystallizes in space group P\overline 1 with Z′ = 4, but the structure closely mimics the monoclinic space group P21/b with Z′ = 2. The molecules of (I) are linked by a combination of N—H⋯O and C—H⋯O hydrogen bonds into two independent chains of centrosymmetric edge-fused R{_2^2}(18) and R{_6^6}(34) rings. N-Methyl-2-phenoxybenzenesulfonamide, C13H13NO3S, (II), crystallizes in space group P21 with Z′ = 1, and is an example of spontaneous resolution. The molecules are linked by N—H⋯O and C—H⋯O hydrogen bonds into chains of spiro-fused R{_2^2}(12) rings, and these chains are linked into sheets by a single C—H⋯π(arene) hydrogen bond.

A heterometallic polymeric complex: [Cu2(N3)2(medpt)2{Ni(CN)4}]n [medpt is bis(3-aminopropyl)methylamine] Contribution No. IND44.

Ghoshal, D. — 2004-05-15

The structure of the title compound, catena-poly[[di-μ-azido-κ4N1:N1-bis[[bis(3-aminopropyl)methylamine-κ3N]copper(II)]]-μ-cyano-[dicyanonickel(II)]-μ-cyano], [Cu2(N3)2(medpt)2{Ni(CN)4}]n [medpt is bis(3-aminopropyl)methylamine, C7H19N2] or [Cu2Ni(CN)4(N3)2(C7H19N3)2]n, is a one-dimensional heterometallic covalent chain where Ni(CN)42− functions as a molecular ion bridge. The Ni atom sits on the centre of inversion. The chain undergoes hydrogen-bonding interactions, forming a three-dimensional supramolecular network.

2-(4-Nitrophenoxy)benzoic acid: a three-dimensional hydrogen-bonded framework in a triclinic structure having Z′ = 3

Glidewell, C. — 2004-05-15

The title compound, C13H9NO5, crystallizes in space group P\overline 1, with Z′ = 3. The molecules are linked by O—H⋯O hydrogen bonds [H⋯O = 1.79–1.81 Å, O⋯O = 2.625 (3)–2.648 (3) Å and O—H⋯O = 172–176°] into two types of R_2^2(8) dimer, only one of which is centrosymmetric. An extensive series of soft hydrogen bonds, of C—H⋯O and C—H⋯π(arene) types, links the dimers into a three-dimensional framework.

1-Bromo-2,6-dihydroxybenzene containing R44(8) rings and C(2) helices

Kirsop, P. — 2004-05-15

Molecules of the title compound (also known as 2-bromoresorcinol), C6H5BrO2, are essentially planar and possess normal geometrical parameters. The crystal packing is influenced by O—H⋯O and O—H⋯O/Br hydrogen bonds and π–π stacking interactions, resulting in a distinctive high-symmetry structure containing R{_4^4}(8) rings and helical C(2) chains.

(R)-2,3,4,5-Tetrahydro-2,2,4-trimethyl-1,5-benzothiazepine and rac-5-benzoyl-2,3,4,5-tetrahydro-2,2,4-trimethyl-1,5-benzothiazepine: chains built from N—H⋯S and C—H⋯π(arene) hydrogen bonds

Muthukumar, M. — 2004-05-15

Molecules of (R)-2,3,4,5-tetrahydro-2,2,4-trimethyl-1,5-benzothiazepine, C12H17NS, are linked into spiral C(5) chains by a single N—H⋯S hydrogen bond, while molecules of rac-5-benzoyl-2,3,4,5-tetrahydro-2,2,4-trimethyl-1,5-benzothiazepine, C19H21NOS, are linked into zigzag chains by a C—H⋯π(arene) hydrogen bond.

Two oxazane macrocycles

Cox, P.J. — 2004-05-15

The 20-membered ring in 1,7,11,17-tetraoxa-2,6,12,16-tetraazacycloeicosane tetrahydrochloride, C12H32N4O44+·4Cl−, adopts an endo conformation, while the 18-membered ring in 1,6,10,15-tetraoxa-2,5,11,14-tetraazacyclooctadecane tetrahydrochloride, C10H28N4O44+·4Cl−, lies about an inversion centre and adopts a symmetrical conformation. In the crystal structures of both compounds, the cations and chloride anions are linked by N—H⋯Cl hydrogen bonds into planar sheets of molecules; the sheets are linked into three-dimensional networks via C—H⋯Cl hydrogen bonds.

2,3-Bis[(4-methylphenyl)sulfanyl]-4H-1-benzothiopyran-4-one 1,1-dioxide forms a framework built from C—H⋯O, C—H⋯π(arene) and π–π interactions

Glidewell, C. — 2004-05-15

Molecules of the title comound, C23H18O3S3, are linked into sheets by a combination of one C—H⋯O hydrogen bond and two C—H⋯π(arene) hydrogen bonds, and these sheets are weakly linked into a three-dimensional structure by means of a single aromatic π–π stacking interaction.

N,N′-Propylenedioxybis(2,4,6-trimethylbenzenesulfonamide): molecules of unexpected conformation form a molecular ladder built from two independent N—H⋯O=S hydrogen bonds

Wardell, S.M.S.V. — 2004-05-15

Molecules of the title compound, C21H30N2O6S2, adopt a skeletal conformation which does not possess even approximate internal symmetry. The molecules are linked by two N—H⋯O=S hydrogen bonds [H⋯O = 1.97 Å (×2), N⋯O = 2.865 (2) and 2.864 (2) Å, and N—H⋯O = 160 and 159°] into molecular ladders, alternatively described as chains of edge-fused R_2^2(20) rings.

Hydrogen bonding in substituted nitroanilines: hydrogen-bonded sheets in 4-iodo-3-nitroaniline

Garden, S.J. — 2004-05-15

In the title compound, C6H5IN2O2, the nitro group is disordered over two sets of sites, each with 0.5 occupancy, and the amino N atom is pyramidal. The molecules are linked into sheets by a combination of three-centre N—H⋯(O)2 hydrogen bonds involving alternative pairs of O-atom sites and two-centre N—H⋯N hydrogen bonds involving the pyramidal amino group.

Hydrates of tin tetrachloride

Genge, A.R.J. — 2004-04-15

The crystal structures of the tri- and tetrahydrate of tin tetrachloride, viz. diaquatetrachlorotin(IV) monohydrate, [SnCl4(H2O)2]·H2O, and diaquatetrachlorotin(IV) dihydrate, [SnCl4(H2O)2]·2H2O, are reported and shown to contain the cis-[SnCl4(H2O)2] species and water molecules in both cases. The trihydrate contains chains of the tin species linked by a single hydrogen-bonded water molecule, whilst the tetrahydrate has a three-dimensional network. In addition, there are O—H⋯Cl interactions present.

2-Nitrophenoxyacetanilide: a chain of rings generated by C—H⋯O hydrogen bonds

Glidewell, C. — 2004-04-15

In molecules of the title compound, C14H12N2O4, the conformation is dominated by an intramolecular N—H⋯O hydrogen bond in which one of the nitro O atoms is the acceptor. The molecules are linked by paired C—H⋯O hydrogen bonds [H⋯O = 2.41 Å, C⋯O = 3.2990 (17) Å and C—H⋯O = 156°] into centrosymmetric R_2^2(14) dimers; these dimers are linked weakly into chains of alternating R_2^2(14) and R_4^4(40) rings by a second C—H⋯O hydrogen bond [H⋯O = 2.55 Å, C⋯O = 3.5006 (15) Å and C—H⋯O = 162°].

2-Amino-3-hydroxy-4-phenylthiazolium chloride: π-stacked hydrogen-bonded chains of edge-fused R_{\bf 4}^{\bf 2}(11) rings

Glidewell, C. — 2004-04-15

In the title compound, C9H9N2OS+·Cl−, the cations exhibit amidinium-type delocalization of the positive charge. The ions are linked by one O—H⋯Cl hydrogen bond and two N—H⋯Cl hydrogen bonds into chains of edge-fused R_4^2(11) rings. The chains are linked into sheets by a π–π stacking interaction.

(Cyclohexylideneamino)oxyacetic acid and [chloro(phenyl)methyleneamino]oxyacetic acid: hydrogen-bonded R_2^2(8) dimers and aromatic π–π stacking interactions

Glidewell, C. — 2004-04-15

Molecules of (cyclohexylideneamino)oxyacetic acid, C8H13NO3, (I), are linked into centrosymmetric dimers by pairs of O—H⋯O hydrogen bonds [H⋯O = 1.84 Å, O⋯O = 2.6782 (12) Å and O—H⋯O = 178°]. In [chloro(phenyl)methyleneamino]oxyacetic acid, C9H8ClNO3, (II), the molecules are similarly linked into centrosymmetric dimers by pairs of O—H⋯O hydrogen bonds [H⋯O = 1.79 Å, O⋯O = 2.6329 (17) Å and O—H⋯O = 176°], and these dimers are weakly linked into chains by a single type of aromatic π–π stacking interaction.

{Tris[4-(1H-pyrazol-3-yl)-3-azabut-3-enyl]amine}iron(II) diperchlorate monohydrate

Hardie, M.J. — 2004-04-15

In the title complex, [Fe(C18H24N10)](ClO4)2·H2O, the complex cation adopts a capped trigonal antiprismatic stereochemistry, with a long Fe–amine interaction [2.7468 (16) Å]. The Fe centre in the asymmetric unit is fully high-spin at 100 K. Hydrogen bonding assembles dimeric units, which are then linked by further hydrogen bonding into chains running parallel to the crystallographic a axis.

Molecular conformation and supramolecular aggregation in two fused pyrazoles: π-stacked R_{\bf 2}^{\bf 2}(6) dimers in 2,8,8-trimethyl-6,7,8,9-tetrahydropyrazolo[2,3-a]quinazolin-6-one, and sheets of alternating R_2^2(12) and R_6^6(48) rings in 3-tert-butyl-4′,4′-dimethyl-1-phenyl-4,5,6,7-tetrahydro-1H-pyrazolo[3,4-b]pyridine-5-spiro-1′-cyclohexane-2′,6′-dione

Low, J.N. — 2004-04-15

In 2,8,8-trimethyl-6,7,8,9-tetrahydropyrazolo[2,3-a]quinazolin-6-one, C13H15N3O, (I), the heterobicyclic system is planar and exhibits peripheral ten π-electron delocalization. In 3-tert-butyl-4′,4′-dimethyl-1-phenyl-4,5,6,7-tetrahydro-1H- pyrazolo[3,4-b]pyridine-5-spiro-1′-cyclohexane-2′,6′-dione, C23H25N3O2, (II), the pyrazole ring exhibits marked bond fixation, while the reduced pyridine ring adopts a half-chair conformation. Molecules of (I) are linked into centrosymmetric R_2^2(6) dimers by a single C—H⋯N hydrogen bond [H⋯N = 2.50 Å, C⋯N = 3.3397 (17) Å and C—H⋯N = 148°], and these dimers are linked into chains by a single π–π stacking interaction. In (II), the combined action of one N—H⋯O hydrogen bond [H⋯O = 2.40 Å, N⋯O = 3.2248 (15) Å and N—H⋯O = 157°] and one C—H⋯O hydrogen bond [H⋯O = 2.48 Å, C⋯O = 3.407 (2) Å and C—H⋯O = 164°] links the molecules into sheets built from alternating centrosymmetric R_2^2(12) and R_6^6(48) rings; there is a weak C—H⋯N interaction [H⋯N = 2.60 Å, C⋯N = 3.5149 (18) Å and C—H⋯N = 154°] between molecules in adjacent sheets.

μ-Ethane-1,2-diylbis(diphenylphosphine oxide)-κ2O:O′-bis[dibenzyldichlorotin(IV)]: a centrosymmetric complex containing trigonal-bipyramidal tin(IV), linked into chains of rings by C—H⋯π(arene) hydrogen bonds

Mohamed, E.M. — 2004-04-15

The title compound, [Sn2Cl4(C7H7)4(C26H24O2P2)], (I), was isolated from the reaction of 1,2-bis(diphenylphosphino)ethane with dibenzyltin(IV) dichloride in the presence of air. The molecules of (I) lie across centres of inversion in space group C2/c and contain five-coordinate Sn atoms. The molecules are linked into chains of rings by a single C—H⋯π(arene) hydrogen bond.

(E)-1-(2-Hydroxyphenyl)propan-2-one O-methyloxime forms hydrogen-bonded chains of edge-fused R\bf{_4^4}(16) and R\bf{_4^4}(24) rings

Glidewell, C. — 2004-04-15

The title compound, C10H13NO2, crystallizes with Z′ = 2 in space group P\overline 1. The molecules are linked by two O—H⋯N hydrogen bonds [H⋯O = 1.97 and 1.98 Å, O⋯N = 2.810 (2) and 2.815 (2) Å, and O—H⋯N = 175 and 174°] and by one C—H⋯O hydrogen bond [H⋯O = 2.50 Å, C⋯O = 3.313 (2) Å and C—H⋯O = 144°] into chains of edge-fused centrosymmetric rings in which {R_4^4}(16) and {R_4^4}(24) rings alternate.

Tetragonal CeNbO4 at 1073 K in air and in vacuo

Skinner, S.J. — 2004-04-15

The structure of the high-temperature scheelite-type polymorph of cerium niobium tetraoxide, CeNbO4, has been determined using time-of-flight neutron powder diffraction data collected both in situ at 1073 K in air and in vacuo. In both cases, the structure was found to be tetragonal, with I41/a symmetry and without any significant deviation from the stoichiometric composition.

The imide tautomer of sulfasalazine

Blake, A.J. — 2004-04-15

The title compound, 5-{4-[(2-pyridylideneamino)sulfonyl]phenyldiazenyl}salicylic acid, C18H14N4O5S, crystallizes as the imide tautomer in the monoclinic space group P21/c. In addition to an intramolecular O—H⋯O hydrogen bond, intermolecular O—H⋯O interactions link adjacent molecules into helices, which are connected by pairwise N—H⋯N interactions into two-dimensional hydrogen-bonded layers. Both the molecular conformation and the packing differ from those seen in the triclinic amide form [Filip et al. (2001). Acta Cryst. C57, 435–436].

N—H⋯N hydrogen bonding in 4,6-diphenyl-2-pyrimidinylamine isolated from the plant Justicia secunda (Acanthaceae)

Gallagher, J.F. — 2004-04-15

The title compound, C16H13N3, isolated from Justicia secunda (Acanthaceae), comprises two molecules (which differ slightly in conformation) in the asymmetric unit of space group P\overline 1. Intermolecular Namino—H⋯Npyrm interactions (Npyrm is a pyrimidine ring N atom) involve only one of the two donor amino H atoms and pyrimidine N atoms per molecule, forming dimeric units via R{_2^2}(8) rings, with N⋯N distances of 3.058 (2) and 3.106 (3) Å, and N—H⋯N angles of 172.7 (18) and 175.8 (17)°. The dimers are linked by C—H⋯π(arene) contacts, with an H⋯centroid distance of 2.77 Å and a C—H⋯centroid angle of 141°.

Open access article in Acta Crystallographica Section C: Crystal Structural Communications

(E)-3-(Benzo[b]thio­phen-2-yl)-2-(3,4,5-trimethoxy­phen­yl)acrylonitrile and (Z)-3-(benzo[b]thio­phen-2-yl)-2-(3,4-dimethoxy­phen­yl)acrylonitrile. Corrigendum

Two new XP(O)[NHC(CH3)3]2 phos­phor­amidates, with X = (CH3)2N and [(CH3)3CNH]2P(O)(O). Corrigendum

A three-dimensional tin(II) phosphon­atobenzene­sulfonate with Sn4O12 clusters. Corrigendum

Bis(2,4-penta­nedionato)cobalt(II)

N-{N-[2-(3,5-Difluoro­phenyl)acetyl]-(S)-alanyl}-(S)-phenyl­glycine tert-butyl ester (DAPT): an inhibitor of γ-secretase, revealing fine electronic and hydrogen-bonding features

Two isomorphous crotonatolanthanide complexes: tetra-μ-but-2-enoato-bis­[diaqua­(but-2-enoato)Ln]–2,6-diamino­purine (1/2) (Ln = Dy and Ho). Corrigendum

μ2-Acetato-κ2O:O′-tris­(μ2-ferrocene­carboxyl­ato-κ2O:O′)bis­[(N,N-di­methyl­formamide-κO)copper(II)]. Corrigendum

Strontium tetra­fluoro­borate. Erratum

The zwitterion of 4-nitro-2-{(E)-[2-(piperidin-1-yl)eth­yl]imino­meth­yl}­phenol

Imidazolium-based ionic liquid salts: 3,3′-dimethyl-1,1′-(1,4-phenyl­ene­dimethyl­ene)diimidazolium bis­(tetra­fluoro­borate) and 3,3′-di-n-butyl-1,1′-(1,4-phenyl­enedimethyl­ene)di­imid­azolium bis­(trifluoro­methane­sulfonate)

Setting ambiguity in C2/c with dibromidotetra­kis(1H-pyrazole-κN2)manganese(II) as an example. Addendum

Accurate stereochemistry for two related 22,26-epimino­cholestene derivatives

Lupulin structures revisited

A novel heterocyclic compound: catena-poly[[[diaquasodium(I)]-di-μ-aqua] hemi(1,5-dihydroxy-4,8,9-trioxa-2,6-diazabicyclo[3.3.1]nona-2,6-diene-3,7-diolate)]. Retraction

Carbon­yl–carbonyl, carbon­yl–π and carbon­yl–halogen dipolar inter­actions as the directing motifs of the supra­molecular structure of ethyl 6-chloro-2-oxo-2H-chromene-3-carboxyl­ate and ethyl 6-bromo-2-oxo-2H-chromene-3-carboxyl­ate

4,5-Dibromo­phthalimide forms two centrosymmetric dimers, one linked by C—H⋯O hydrogen bonds and one by N—H⋯O hydrogen bonds

Dimorphism in 4,4,6,6-tetra­chloro-2,2-(2,2-dimethyl­propane-1,3-di­oxy)cyclotriphosphazene and 6,6-di­chloro-2,2:4,4-bis­(2,2-dimethyl­propane-1,3-di­oxy)cyclotriphosphazene

4-Cyano­benzaldehyde isonicotinoylhydrazone monohydrate: a three-dimensional hydrogen-bonded ­framework structure

6-(4-Fluoro­phen­yl)-8-phenyl-2,3-dihydro-4H-imidazo[5,1-b][1,3]thiazin-4-one: an unusual [6–5] fused-ring system

1-(6-Amino-1,3-benzodioxol-5-yl)-3-(4-pyrid­yl)prop-2-en-1-one crystallizes with Z′ = 2: hydrogen-bonded supra­molecular substructures in one and two dimensions, each containing only one type of mol­ecule

Five symmetrically substituted 2-aryl-3-benzyl-1,3-thia­zolidin-4-ones: supra­molecular structures in zero, one and two dimensions

Escitalopram oxalate: co-existence of oxalate dianions and oxalic acid mol­ecules in the same crystal

2,3-Dimethoxy­benzaldehyde isonicotinoyl­hydrazone chloro­form monosolvate, and the mono- and dihydrates of 3,4,5-trimethoxy­benzaldehyde isonicotinoyl­hydrazone: hydrogen-bonded supra­molecular structures in one, two and three dimensions

3-Nitro­benzaldehyde isonicotinoyl­hydrazone monohydrate redetermined at 120 K: sheets built from O—H⋯O, O—H⋯N, N—H⋯O and C—H⋯O hydrogen bonds

1,4,8,11-Tetra­azacyclo­tetra­decane anti­mony(III) sulfide

Hydrogen-bonded chains in 3-tert-butyl-5-[(4-methoxy­benz­yl)amino]-1-phenyl-1H-pyrazole and tetra­molecular hydrogen-bonded aggregates in 5-[(benzotriazol-1-ylmeth­yl)(4-methoxy­benz­yl)amino]-3-tert-butyl-1-phenyl-1H-pyrazole

Three substituted 4-pyrazolylbenzoates: hydrogen-bonded supra­mol­ecular structures in one, two and three dimensions

Three ethyl 5-amino-1-aryl-1H-imidazole-4-carboxylates: hydrogen-bonded supra­molecular structures in one, two and three dimensions

Two square-planar palladium(II) complexes with P,O-bidentate hybrid ligands

The concomitant crystallization of two polymorphs of 1-de­oxy-α-d-tagatose

7-Amino-2-tert-butyl-5-methyl­pyrazolo[1,5-a]pyrimidine: a three-dimensional framework structure built from two N—H⋯N hydrogen bonds

Cocrystals composed of 4,4′-(fluorene-9,9-di­yl)diphenol and 6-methyl-2H-pyridone

Hydrogen-bonded chains of rings in methyl 4-[(5-methyl-1H-pyrazol-3-yl)amino]-3-nitro­benzoate and hydrogen-bonded sheets in methyl 1-(5-methyl-1H-pyrazol-3-yl)-1H-benzimidazole-5-carboxyl­ate

Ammonium scandium tetra­fluoride

Dichloro­(4,10-dimethyl-1,4,7,10-tetra­azabicyclo­[5.5.2]tetra­decane)­iron(III) hexa­fluoro­phosphate

A second polymorph of [H3N(CH2)3NH3][V4O10]

Solvent-free synthesis and crystal structure of (Ph3PI)I5, the third member in the series Ph3P(I2)n (n = 1, 2 and 3)

3-Nitro­phenyl­acetic acid: a three-dimensional hydrogen-bonded framework structure containing sub­structures in zero, one and two dimensions

Effects of d-orbital occupancy on the geometry of the trigonal–bipyramidal complexes [MIICl3(Hdabco)(dabco)]n, where M is Mn, Co, Ni or Cu and dabco is 1,4-diaza­bicyclo­[2.2.2]octane

Four substituted benzohydrazides: hydrogen-bonded structures in one, two and three dimensions

Comparison of copper imine and amine podates: geometric consequences of podand size and donor type

Chloro­(diethyl­enetriamine)copper(II) chloride: a disordered quasi-one-dimensional structure

3-[5-(4-Bromo­phenyl)-1H-pyrazol-3-ylamino]-5,5-dimethyl­cyclo­hex-2-en-1-one–(Z)-3-(4-bromo­phenyl)-3-chloro­acrylonitrile (2/1): a stoichiometric cocrystal of a reaction product with one of its early precursors

Hydrogen-bonded chains in racemic 2-benzyl-3-(2-bromo­phen­yl)­propiono­nitrile and hydrogen-bonded sheets in methyl 2-benzyl-2-cyano-3-phenyl­propionate

2,6-Dibromo-3,5-dimethyl­pyridine and 2,6-diiodo-3,5-dimethyl­pyridine

An unusual example of a linearly coordinated acetone ligand in a six-coordinate iron(II) complex

5-(2-Hydr­oxy-4,4-dimethyl-6-oxo­cyclo­hex-1-en­yl)-3-methyl-2-(methyl­sulfan­yl)-6-phenyl-7H-pyrrolo[2,3-d]pyrimidin-4(3H)-one monohydrate: complex sheets generated by multiple hydrogen bonds

Three substituted (E)-3-aryl-2-(thienyl)acrylonitriles: isolated mol­ecules, simple hydrogen-bonded chains and hydrogen-bonded sheets

A hydrogen-bonded chain of rings in 7-amino-5-tert-butyl-2-methyl­pyrazolo[1,5-a]pyrimidine, and a hydrogen-bonded framework structure in 3,7-diamino-2,5-dimethyl­pyrazolo[1,5-a]pyrimidine mono­hydrate

3-(5-Chloro-3-methyl-1-phenyl­pyrazol-4-yl)-1,5-diphenyl­pentane-1,5-dione: sheets built from C—H⋯O and C—H⋯π(arene) hydrogen bonds

3-(4-Methoxy­phen­yl)-7,7-dimethyl-1,6,7,8-tetra­hydro­pyrazolo[3,4-b]quinolin-5-one: a chain of centrosymmetric rings built from N—H⋯N and C—H⋯π(arene) hydrogen bonds

Poly[propane-1,3-diyldiammonium tetra-μ-selenito-trizinc dihydrate]

A polymeric solvent-free variant of a hydridomagnesium inverse crown

Poly[(2,2′-bipyridine-κ2N,N′)(μ2-dihydrogen phosphato-κ2O:O′)(μ2-hydrogen phosphato-κ2O:O′)aluminium(III)], Al(2,2′-bipy)(HPO4)(H2PO4), a layered inorganic–organic hybrid material

Tetra­thia­fulvalene revisited

2,4-Dimethyl­benzaldehyde isonicotinoylhydrazone trihydrate: a three-dimensional hydrogen-bonded framework structure

1-(Isopropyl­ideneamino)guanidinium 2-nitro­benzoate: formation of corrugated sheets from R22(8) and R64(16) rings

N-(2-Hydr­oxy-3-iodo-5-nitro­benzyl­idene)-3-nitro­aniline: conformational isomers linked into complex sheets by five C—H⋯O hydrogen bonds and a two-centre iodo–nitro inter­action

5-Fluoro­uracil and thymine form a crystalline solid solution

4-Iodo-N,N-bis(2-nitro­phenyl­sulfon­yl)aniline: a three-dimensional framework structure built from six independent C—H⋯O hydrogen bonds

{Bis(3,5-Di-tert-butyl-2-oxidobenzyl)[2-(N,N-dimethyl­amino)ethyl]amine-κ4N,N′,O,O′}zinc(II) and {bis­(3-tert-butyl-5-methyl-2-oxidobenzyl)[2-(N,N-dimethyl­amino)ethyl]amine-κ4N,N′,O,O′}(tetra­hdyrofuran)zinc(II)

Three substituted (Z)-5-benzyl­idene-2-thioxothia­zolidin-4-ones: hydrogen-bonded dimers that can be effectively isolated or linked into chains either by aromatic π–π stacking inter­actions or by dipolar carbon­yl–carbonyl inter­actions

Four 2-aryl-8,8-dimethyl-6,7,8,9-tetra­hydro­pyrazolo[2,3-a]quinazolin-6-ones: isolated mol­ecules, hydrogen-bonded dimers, and π-stacked chains of hydrogen-bonded dimers

2-Bromo-1,3-bis­(bromo­meth­yl)­benzene, with Z′ = 1.5: whole-mol­ecule disorder of one of the two independent mol­ecules

1,2-Bis(diphenyl­phosphino)benzene and two related mono-methio­dides, [o-C6H4(PR2)(PR2Me)]I (R = Ph or Me)

Hydrogen-bonded chains of rings linked by iodo–carbonyl inter­actions in 5-iodo­isatin and hydrogen-bonded sheets in 7-trifluoro­methyl­isatin

(1Z,2Z)-1,2-Bis(3-methyl-2,3-dihydro-1,3-benzothiazol-2-ylidene)hydrazine

Arene–perfluoro­arene inter­actions in crystal engineering. XV. Ferrocene–deca­fluoro­biphenyl (1/1)For Part XIV, see Collings et al. (2006).

Sheets built from C—H⋯O and C—H⋯π(arene) hydrogen bonds in (2RS,6SR)-N-diphenyl­acetyl-2,6-diphenylpiperidin-4-one and (2RS,3SR,5RS,6SR)-3,5-dimethyl-N-phenyl­acetyl-2,6-diphenylpiperidin-4-one

Formation of ladders from R44(8) and R66(12) rings in 8-hydroxy­quinolinium chloride monohydrate: comparisons with the supra­molecular arrangements in related salts

2,4-Dinitro­phenyl­hydrazine, redetermined at 120 K: a three-dimensional framework built from N—H⋯O, N—H⋯(O)2, N—H⋯π(arene) and C—H⋯O hydrogen bonds

2-(4-Chloro­anilino)- and 2-(4-methoxy­anilino)-1,2-diphenyl­ethanone

PbZn1/3Nb2/3O3 at 4.2 and 295 K

(Nitrato-κ2O,O′)bis­(triethanol­amine-κ4N,O,O′,O′′)lanthanum(III) dinitrate

Conformations of three heterocyclic perhydro­pyrrolobenzofurans and polymeric assembly via co-operative inter­molecular C—H⋯O hydrogen bonds

An ortho­rhom­bic polymorph of 10,11-dihydro­carbamazepine

N-(2-Methoxy-6-oxo-1,6-dihydropyrimidin-4-yl)­formamide: hydrogen-bonded sheets of centrosymmetric R22(8) and R64(28) rings

A three-dimensional framework of π-stacked hydrogen-bonded chains in benzyl 4-chloro-3-nitro­benzoate, and chains of hydrogen-bonded rings in benzyl 4-nitro­benzoate, redetermined at 120 K

Hydrogen-bonded sheets in racemic cis-(2,2′-bipyridyl-κ2N,N′)oxo(pentane-2,4-dionato-κ2O,O′)(thio­cyanato-κN)vanadium(IV)

(E)-3-(Benzo[b]thiophen-2-yl)-2-(3,4,5-trimethoxyphenyl)acrylonitrile and (Z)-3-(benzo[b]thiophen-2-yl)-2-(3,4-dimethoxyphenyl)acrylonitrile. Corrigendum

Two new XP(O)[NHC(CH3)3]2 phosphoramidates, with X = (CH3)2N and [(CH3)3CNH]2P(O)(O). Corrigendum

A three-dimensional tin(II) phosphonatobenzenesulfonate with Sn4O12 clusters. Corrigendum

Bis(2,4-pentanedionato)cobalt(II)

N-{N-[2-(3,5-Difluorophenyl)acetyl]-(S)-alanyl}-(S)-phenylglycine tert-butyl ester (DAPT): an inhibitor of γ-secretase, revealing fine electronic and hydrogen-bonding features

Two isomorphous crotonatolanthanide complexes: tetra-μ-but-2-enoato-bis[diaqua(but-2-enoato)Ln]–2,6-diaminopurine (1/2) (Ln = Dy and Ho). Corrigendum

μ2-Acetato-κ2O:O′-tris(μ2-ferrocenecarboxylato-κ2O:O′)bis[(N,N-dimethylformamide-κO)copper(II)]. Corrigendum

Strontium tetrafluoroborate. Erratum

The zwitterion of 4-nitro-2-{(E)-[2-(piperidin-1-yl)ethyl]iminomethyl}phenol

Imidazolium-based ionic liquid salts: 3,3′-dimethyl-1,1′-(1,4-phenylenedimethylene)diimidazolium bis(tetrafluoroborate) and 3,3′-di-n-butyl-1,1′-(1,4-phenylenedimethylene)diimidazolium bis(trifluoromethanesulfonate)

Setting ambiguity in C2/c with dibromidotetrakis(1H-pyrazole-κN2)manganese(II) as an example. Addendum

Accurate stereochemistry for two related 22,26-epiminocholestene derivatives

Carbonyl–carbonyl, carbonyl–π and carbonyl–halogen dipolar interactions as the directing motifs of the supramolecular structure of ethyl 6-chloro-2-oxo-2H-chromene-3-carboxylate and ethyl 6-bromo-2-oxo-2H-chromene-3-carboxylate

4,5-Dibromophthalimide forms two centrosymmetric dimers, one linked by C—H⋯O hydrogen bonds and one by N—H⋯O hydrogen bonds

Dimorphism in 4,4,6,6-tetrachloro-2,2-(2,2-dimethylpropane-1,3-dioxy)cyclotriphosphazene and 6,6-dichloro-2,2:4,4-bis(2,2-dimethylpropane-1,3-dioxy)cyclotriphosphazene

4-Cyanobenzaldehyde isonicotinoylhydrazone monohydrate: a three-dimensional hydrogen-bonded framework structure

6-(4-Fluorophenyl)-8-phenyl-2,3-dihydro-4H-imidazo[5,1-b][1,3]thiazin-4-one: an unusual [6–5] fused-ring system

1-(6-Amino-1,3-benzodioxol-5-yl)-3-(4-pyridyl)prop-2-en-1-one crystallizes with Z′ = 2: hydrogen-bonded supramolecular substructures in one and two dimensions, each containing only one type of molecule

Five symmetrically substituted 2-aryl-3-benzyl-1,3-thiazolidin-4-ones: supramolecular structures in zero, one and two dimensions

Escitalopram oxalate: co-existence of oxalate dianions and oxalic acid molecules in the same crystal

2,3-Dimethoxybenzaldehyde isonicotinoylhydrazone chloroform monosolvate, and the mono- and dihydrates of 3,4,5-trimethoxybenzaldehyde isonicotinoylhydrazone: hydrogen-bonded supramolecular structures in one, two and three dimensions

3-Nitrobenzaldehyde isonicotinoylhydrazone monohydrate redetermined at 120 K: sheets built from O—H⋯O, O—H⋯N, N—H⋯O and C—H⋯O hydrogen bonds

1,4,8,11-Tetraazacyclotetradecane antimony(III) sulfide

Hydrogen-bonded chains in 3-tert-butyl-5-[(4-methoxybenzyl)amino]-1-phenyl-1H-pyrazole and tetramolecular hydrogen-bonded aggregates in 5-[(benzotriazol-1-ylmethyl)(4-methoxybenzyl)amino]-3-tert-butyl-1-phenyl-1H-pyrazole

Three substituted 4-pyrazolylbenzoates: hydrogen-bonded supramolecular structures in one, two and three dimensions

Three ethyl 5-amino-1-aryl-1H-imidazole-4-carboxylates: hydrogen-bonded supramolecular structures in one, two and three dimensions

The concomitant crystallization of two polymorphs of 1-deoxy-α-d-tagatose

7-Amino-2-tert-butyl-5-methylpyrazolo[1,5-a]pyrimidine: a three-dimensional framework structure built from two N—H⋯N hydrogen bonds

Cocrystals composed of 4,4′-(fluorene-9,9-diyl)diphenol and 6-methyl-2H-pyridone

Hydrogen-bonded chains of rings in methyl 4-[(5-methyl-1H-pyrazol-3-yl)amino]-3-nitrobenzoate and hydrogen-bonded sheets in methyl 1-(5-methyl-1H-pyrazol-3-yl)-1H-benzimidazole-5-carboxylate

Ammonium scandium tetrafluoride

Dichloro(4,10-dimethyl-1,4,7,10-tetraazabicyclo[5.5.2]tetradecane)iron(III) hexafluorophosphate

3-Nitrophenylacetic acid: a three-dimensional hydrogen-bonded framework structure containing substructures in zero, one and two dimensions

Effects of d-orbital occupancy on the geometry of the trigonal–bipyramidal complexes [MIICl3(Hdabco)(dabco)]n, where M is Mn, Co, Ni or Cu and dabco is 1,4-diazabicyclo[2.2.2]octane

Chloro(diethylenetriamine)copper(II) chloride: a disordered quasi-one-dimensional structure

3-[5-(4-Bromophenyl)-1H-pyrazol-3-ylamino]-5,5-dimethylcyclohex-2-en-1-one–(Z)-3-(4-bromophenyl)-3-chloroacrylonitrile (2/1): a stoichiometric cocrystal of a reaction product with one of its early precursors

Hydrogen-bonded chains in racemic 2-benzyl-3-(2-bromophenyl)propiononitrile and hydrogen-bonded sheets in methyl 2-benzyl-2-cyano-3-phenylpropionate

2,6-Dibromo-3,5-dimethylpyridine and 2,6-diiodo-3,5-dimethylpyridine

5-(2-Hydroxy-4,4-dimethyl-6-oxocyclohex-1-enyl)-3-methyl-2-(methylsulfanyl)-6-phenyl-7H-pyrrolo[2,3-d]pyrimidin-4(3H)-one monohydrate: complex sheets generated by multiple hydrogen bonds

Three substituted (E)-3-aryl-2-(thienyl)acrylonitriles: isolated molecules, simple hydrogen-bonded chains and hydrogen-bonded sheets

A hydrogen-bonded chain of rings in 7-amino-5-tert-butyl-2-methylpyrazolo[1,5-a]pyrimidine, and a hydrogen-bonded framework structure in 3,7-diamino-2,5-dimethylpyrazolo[1,5-a]pyrimidine monohydrate

3-(5-Chloro-3-methyl-1-phenylpyrazol-4-yl)-1,5-diphenylpentane-1,5-dione: sheets built from C—H⋯O and C—H⋯π(arene) hydrogen bonds

3-(4-Methoxyphenyl)-7,7-dimethyl-1,6,7,8-tetrahydropyrazolo[3,4-b]quinolin-5-one: a chain of centrosymmetric rings built from N—H⋯N and C—H⋯π(arene) hydrogen bonds

Tetrathiafulvalene revisited

2,4-Dimethylbenzaldehyde isonicotinoylhydrazone trihydrate: a three-dimensional hydrogen-bonded framework structure

1-(Isopropylideneamino)guanidinium 2-nitrobenzoate: formation of corrugated sheets from R22(8) and R64(16) rings

N-(2-Hydroxy-3-iodo-5-nitrobenzylidene)-3-nitroaniline: conformational isomers linked into complex sheets by five C—H⋯O hydrogen bonds and a two-centre iodo–nitro interaction

5-Fluorouracil and thymine form a crystalline solid solution

4-Iodo-N,N-bis(2-nitrophenylsulfonyl)aniline: a three-dimensional framework structure built from six independent C—H⋯O hydrogen bonds

{Bis(3,5-Di-tert-butyl-2-oxidobenzyl)[2-(N,N-dimethylamino)ethyl]amine-κ4N,N′,O,O′}zinc(II) and {bis(3-tert-butyl-5-methyl-2-oxidobenzyl)[2-(N,N-dimethylamino)ethyl]amine-κ4N,N′,O,O′}(tetrahdyrofuran)zinc(II)

Three substituted (Z)-5-benzylidene-2-thioxothiazolidin-4-ones: hydrogen-bonded dimers that can be effectively isolated or linked into chains either by aromatic π–π stacking interactions or by dipolar carbonyl–carbonyl interactions

Four 2-aryl-8,8-dimethyl-6,7,8,9-tetrahydropyrazolo[2,3-a]quinazolin-6-ones: isolated molecules, hydrogen-bonded dimers, and π-stacked chains of hydrogen-bonded dimers

2-Bromo-1,3-bis(bromomethyl)benzene, with Z′ = 1.5: whole-molecule disorder of one of the two independent molecules

1,2-Bis(diphenylphosphino)benzene and two related mono-methiodides, [o-C6H4(PR2)(PR2Me)]I (R = Ph or Me)

Hydrogen-bonded chains of rings linked by iodo–carbonyl interactions in 5-iodoisatin and hydrogen-bonded sheets in 7-trifluoromethylisatin

Arene–perfluoroarene interactions in crystal engineering. XV. Ferrocene–decafluorobiphenyl (1/1)For Part XIV, see Collings et al. (2006).

Sheets built from C—H⋯O and C—H⋯π(arene) hydrogen bonds in (2RS,6SR)-N-diphenylacetyl-2,6-diphenylpiperidin-4-one and (2RS,3SR,5RS,6SR)-3,5-dimethyl-N-phenylacetyl-2,6-diphenylpiperidin-4-one

Formation of ladders from R44(8) and R66(12) rings in 8-hydroxyquinolinium chloride monohydrate: comparisons with the supramolecular arrangements in related salts

2,4-Dinitrophenylhydrazine, redetermined at 120 K: a three-dimensional framework built from N—H⋯O, N—H⋯(O)2, N—H⋯π(arene) and C—H⋯O hydrogen bonds

2-(4-Chloroanilino)- and 2-(4-methoxyanilino)-1,2-diphenylethanone

(Nitrato-κ2O,O′)bis(triethanolamine-κ4N,O,O′,O′′)lanthanum(III) dinitrate

Conformations of three heterocyclic perhydropyrrolobenzofurans and polymeric assembly via co-operative intermolecular C—H⋯O hydrogen bonds

An orthorhombic polymorph of 10,11-dihydrocarbamazepine

N-(2-Methoxy-6-oxo-1,6-dihydropyrimidin-4-yl)formamide: hydrogen-bonded sheets of centrosymmetric R22(8) and R64(28) rings

A three-dimensional framework of π-stacked hydrogen-bonded chains in benzyl 4-chloro-3-nitrobenzoate, and chains of hydrogen-bonded rings in benzyl 4-nitrobenzoate, redetermined at 120 K

Hydrogen-bonded sheets in racemic cis-(2,2′-bipyridyl-κ2N,N′)oxo(pentane-2,4-dionato-κ2O,O′)(thiocyanato-κN)vanadium(IV)

Poly[piperazinium(2+) [hexa-μ-hydrogen phosphito-μ-piperazine-pentazinc(II)]]

Oxalate complexes of the (η6-p-cymene)ruthenium(II) fragment: μ-oxalato-κ2O1,O2:κ2O1′,O2′-bis[(η6-p-cymene)(triphenylphosphine-κP)ruthenium(II)] bis(tetrafluoroborate) and (η6-p-cymene)(oxalato-κ2O,O′)(pyridine-3,5-dicarboxylic acid-κN)ruthenium(II)

Hydrogen-bonded framework structures in 4-[(4-chloro-3-nitrobenzoyl)hydrazinocarbonyl]pyridinium chloride and N-3,5-dinitrobenzoyl-N′-isonicotinoylhydrazine

(–)-(5S,8S,9R,10S,13R,14R)-15,16-Dideoxy-16,17-epoxy-16-oxospongian-15-yl acetate

(3-Hydroxy-2-pyridylmethyl)dimethylammonium dihydrogenphosphate

7-Amino-2,5-dimethylpyrazolo[1,5-a]pyrimidine hemihydrate redetermined at 120 K: a three-dimensional hydrogen-bonded framework

Simple hydrogen-bonded chains in 2,2′-bipyridinium thiocyanate, hydrogen-bonded chains of rings in 2,2′-bipyridinium picrate and hydrogen-bonded sheets in 2,2′-bipyridinium hydrogensulfate

N,N′-Bis(2-chloronicotinoyl)-N-(3-nitrophenyl)hydrazine monohydrate: complex sheets built from O—H⋯N, N—H⋯O and C—H⋯O hydrogen bonds

Neutron diffraction studies of the 1:1 and 2:1 cocrystals of benzene-1,2,4,5-tetracarboxylic acid and 4,4′-bipyridine

4,5,6-Triamino-2-(methylsulfanyl)pyrimidine: π-stacked hydrogen-bonded sheets of R22(8), R22(10) and R66(32) rings

Isolated molecules in 2-ethylsulfanyl-7-methyl-4-(4-methylphenyl)pyrazolo[1,5-a][1,3,5]triazine and hydrogen-bonded sheets of R22(10), R22(16), R44(22) and R44(24) rings in 2-ethylsulfanyl-7-methyl-4-(4-nitrophenyl)pyrazolo[1,5-a][1,3,5]triazine

2,4-Difluorobenzaldehyde benzoylhydrazone and 2,4-dichlorobenzaldehyde benzoylhydrazone are isostructural at 120 K with Z′ = 2: complex sheets built from N—H⋯O, C—H⋯O and C—H⋯π(arene) hydrogen bonds

3-(3-Nitrophenylaminocarbonyl)propionic acid: hydrogen-bonded sheets of alternating R22(8) and R66(36) rings

2-Amino-5-trifluoromethyl-1,3,4-thiadiazole and a redetermination of 2-amino-1,3,4-thiadiazole, both at 120 K: chains of edge-fused R22(8) and R44(10) rings, and sheets of R22(8) and R66(20) rings