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Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890

September 2017 issue

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Cover illustration: Structures that contain hydroxyl and secondary and primary amine groups are sometimes determined incorrectly because of an assumed geometry of these groups from which the applied constraints or restraints were inferred. In such cases, the correct geometry is missed as it is not verified by inspection of the difference electron-density maps. The structure of a molecular salt, C10H13N4+·N3-, has been redetermined from the data published by Qian & Huang [Acta Cryst. (2010), E66, o3086]. The improvement of the present redetermination consists in a correction of the site-occupancy parameter of the bridging H atom between the pyridine rings, as well as of its position. The present study has shown that the bridging H atom (site symmetry 2) is involved in a symmetric N-H...N hydrogen bond, which is one of the longest ever observed [N...N = 2.678 (3) Å]. See: Fábry [Acta Cryst. (2017). E73, 1344-1347].

research communications


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The crystal structure of the title compound, which contains azomethine groups, is reported; its keto and enol tautomeric forms are investigated.

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In the crystal of the title compound, the benzoic acid mol­ecules are linked by O—H⋯O hydrogen bonds, forming inversion dimers with R_{2}^{2}(8) motifs. The dimers are linked further via weak C—H⋯O hydrogen bonds, and S⋯S and S⋯C contact inter­actions into a layer structure.

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The title iridium(III) complex crystallizes as a aceto­nitrile monosolvate and has the IrIII atom in a distorted octa­hedral coordination within a C2N2ClS coordination set.


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The mol­ecular structure of the title compound is characterized by a planarity that allows the formation of (010) sheets. However, the existence of two different conformations of the ethyl fragment introduces the occurrence of discrete disorder due to a mol­ecular overlay.

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The title substance of cerium(IV) bis­(phosphite), Ce(HPO3)2, crystallizes in a trigonal cell and is composed of CeO6 octa­hedra and phosphite tetra­hedra.

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The structure of potassium indium diarsenate(V) is isotypic to TlInAs2O7 structure type (P\overline{1}, Z = 4) and closely related to the KAlP2O7 (P21/c) and RbAlAs2O7 (P\overline{1}) structure types. The framework topology of KInAs2O7 is built of two symmetrically non-equivalent As2O7 groups which share corners with InO6 octa­hedra. The K atoms are located in channels extending along [010].


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The complex title mol­ecule lies across an inversion centre and exhibits a slightly distorted octa­hedral coordination environment for the CoII atom.


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The MnBr2 complex of N2,N6-bis­(di-tert-butyl­phosphan­yl)pyridine-2,6-di­amine (1·MnBr2) co-crystallizes with 5.69% of the monophosphine oxide analogue (1O·MnBr2) and two tetra­hydro­furan (THF) mol­ecules, namely {N2,N6-bis­(di-tert-butyl­phosphan­yl)pyridine-2,6-di­amine}­dibromido­manganese(II)–[bis­(di-tert-butyl­phosphan­yl)({6-[(di-tert-butyl­phosphan­yl)amino]­pyridin-2-yl}amino)­phosphine oxide]di­bromido­manganese(II)–tetra­hydro­furan (0.94/0.06/2), [MnBr2(C21H41N3P2)]0.94[MnBr2(C21H41N3OP2)]0.06·2C4H8O. The 1·MnBr2 and 1O·MnBr2 complexes are connected by weak N—H⋯Br hydrogen bonding into chains extending along [001] with the THF mol­ecules located between the layers formed by these chains.

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The herbicide penoxsulam crystallizes with two independent mol­ecules in the asymmetric unit. The crystal structure is stabilized by C—F⋯π and π–π inter­actions that combine with C—H⋯F and C—H O hydrogen bonds and weak inter­molecular F⋯F short contacts to form a three-dimensional network.

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The title compounds both comprise a tetra­butyl­ammonium cation, a halide anion and an ortho-phenyl­ene bis-urea mol­ecule. Each halide ion shows four N—H⋯X (X = Cl or Br) inter­actions with two urea receptor sites of different bis-urea moieties. A crystallographic inversion centre leads to the formation of a 2:2 arrangement of two halide anions and two bis-urea mol­ecules.

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In each of the title compounds, the cation is conformationally chiral, exhibiting conformational disorder, while two of the nitro groups in the picrate anion also exhibit disorder. In the benzoate salt, the ions are linked into a chain of rings by N—H⋯O hydrogen bonds, whole in the picrate salt, the hydrogen-bonded four-ion aggregate contains four different types of ring.

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In the title oxime ester, the benzoate and furan rings are almost coplanar, making a dihedral angle of 11.68 (9)°. In the crystal, mol­ecules are linked by C—H⋯O hydrogen bonds, forming chains along the a-axis direction.

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In the title compound, the indole ring system makes a dihedral angle of 63.56 (8)° with the plane of the anthracene ring. The conformation about the C=N bond of the –CH2–CH2–N=CH– bridge linking the two units is E. In the crystal, the indole H atom is involved in an inter­molecular N—H⋯π inter­action with the benzene ring of the indole group, leading to the formation of chains along [010].

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The title salt forms a racemate due to disorder of the hy­droxy group [occupancy ratio 0.738 (3):0.262 (3)] at the stereogenic C atom.

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In the title mol­ecule, the central pyrrole ring makes dihedral angles of 9.2 (3) and 67.6 (2)°, respectively, with the eth­oxy carbonyl moiety and the fluoro­phenyl ring. Supra­molecular aggregation is due to off-centric π–π stacking inter­actions involving screw-related pairs of mol­ecules, which are further connected by N—H⋯O and C—H⋯O inter­actions, forming a sinusoidal pattern

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The side product of the cyclo­condensation reaction between ethyl benzimidazole-2-carboxyl­ate and the nitrile imine of the corresponding hydrazonyl chloride, C20H11BrClN5O, crystallized in two crystal forms. Form (1) is a co-crystal of the target compound (without any chlorine substituent) and a side product containing a Cl atom in position 2 of the bromo­phenyl group, C20H12BrN5O·0.143C20H11BrClN5O. (2) contains the pure side product. The slightly different conformation of the ring systems leads to a different packing of (1) and (2), but both crystal structures are dominated by π–π inter­actions.

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The redetermined structure of the title mol­ecular salt possesses one of the longest symmetric N⋯H⋯N hydrogen bonds known [N⋯N = 2.678 (3) Å].

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In the title Zn complex, the ZnII cation is five-coordinated in a distorted trigonal–bipyramidal geometry. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (58.4%), H⋯C/C⋯H (20.3%) and H⋯O/O⋯H (18.3%) inter­actions.

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The characteristic feature of this cadmium(II) complex is the formation of a dimeric bridged structure where the two CdII cations are bridged by S atoms from the N,N-di­allyl­ldi­thio­carbamate ligands.

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The geometry of potassium trans-bi­cyclo­[5.1.0]octane-4-carboxyl­ate monohydrate, a highly strained trans-fused bicyclic ring system, is compared with that of a less-strained cis-bi­cyclo­[5.1.0]octane derivative.

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In the centrosymmetric binuclear title compound, the CdII atoms are linked by a μ2-adipate dianion; the distorted octa­hedral geometry of the metal ion is defined by a ClN2O3 donor set.

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The isolation and crystal structures of the title compounds from Hibiscus sabdariffa (Malvaceae) are described. Hibiscus acid dimethyl sulfoxide monosolvate forms a two-dimensional hydrogen-bonded motif, while hibiscus acid dimethyl ester (Z′ = 2) forms a one-dimensional hydrogen-bonded motif.

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In the crystal of the title compound, C—H⋯O hydrogen bonds and C—O⋯π inter­actions form a two-dimensional network lying parallel to the ab plane.

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K2(SSC-NC4H7—COO)·3H2O or C6H13K2NO5S2 exbibits a highly complex supra­molecular structure in the crystal, which is governed by bridging O– and S-atom coordination, as well as hydrogen bonding.

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The title compound comprises a central pyromellitic di­imide substituted with S atoms and terminal benzyl groups. In the crystal, adjacent mol­ecules are linked by C—H⋯π inter­actions and short S⋯S contacts, forming a two-dimensional network parellel to the (110) plane.

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The inclusion of a methyl­ene group at the thio­amidic N atom of the acetone thio­semicarbazone derivative endows the mol­ecule with greater flexibility and different pathways of association compared to those usually observed in the crystalline structures of these compounds.

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7-Aza­bicyclo­[2.2.1]heptane (7-aza­norbornane) is a bridged heterocyclic nucleus found in epibatidine. The structural characterization of the 7-aza­bicyclo­[2.2.1]heptane parent ring as its hydro­chloride salt, namely 7-aza­bicyclo­[2.2.1]heptan-7-ium chloride, has been carried out.

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The synthesis and crystal structure of a new thio­phene monomer containing an additional 1,2,4-triazole ring are reported. The compound has a V-shaped conformation with the thio­phene ring disordered over two positions by a rotation of approximately 180°.

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The title compound was prepared from an equimolar mixuture of nickel nitrate, phenanthroline and two equivalents of (S)-2-(2-hy­droxy­benzyl­amino)-4-methyl­penta­noic acid. The NiII complex shows a distorted octa­hedral geometry which is stabilized by intra­molecular hydrogen bonds and a weak π–π inter­action.

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The mol­ecular and crystal structure of the title imidazole derivative is reported. The structure features an extensive O—H⋯N, C—H⋯O/N and C—H⋯π(ring) hydrogen-bonding network.

Research communications

The first papers in this new format were published in July 2014. Research communications are longer papers with new text sections designed to help authors bring out the science behind their structure determinations. Figures are included in the published paper and, for the first time in Acta E, individual reports are not limited to single structure determinations. The Research communications format will make Acta E the natural home for structure determinations with interesting science to report.

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Acta E is now included in the Thomson Reuters Emerging Sources Citation Index.

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