Gd₂OSe₂

Gd₂OSe₂ is the first rare-earth monooxy­gen diselenide to be characterized structurally. It is isostructural with the low-pressure form of Dy₂OS₂. Its structure comprises the close packing of Gd-centered bicapped trigonal prisms and Gd-centered distorted octahedra.

CsTiP₂O₇

CsTiP₂O₇ crystallizes in the KAlP₂O₇ structure type. It has a three-dimensional tunnel structure built by the corner-sharing of distorted TiO₆ octahedra and P₂O₇ pyrophosphate groups. The Cs⁺ cations are in the tunnels.

Lanthanum selenite, La₂(SeO₃)₃

The new structure of La₂(SeO₃)₃ consists of LaO₁₀ polyhedra and SeO₃ pyramids sharing faces, edges and vertices. The three-dimensional structure contains pseudo-channels associated with the Se^IV lone pairs.

β-K₂Cr₂O₇

The structure of monoclinic dipotassium dichromate consists of K⁺ cations and Cr₂O₇²⁻ dimers.

RbLi₂Ga₂(BO₃)₃

The structure of RbLi₂Ga₂(BO₃)₃ is an ordered derivative of KZn(BO₃)₃. It exhibits a three-dimensional framework of BO₃ triangles, and LiO₄ and GaO₄ tetrahedra that isolates the Rb atoms in channels extending along the b axis.

(η⁶-Hexa­methylbenzene)(mesidine)­ditriflatoruthenium(II)

The bis­(η⁵-cyclo­penta­dienyl)­methyl­zirconium(IV) methyl­tris­(penta­fluoro­phenyl)­borate ion pair

Polymeric bis­(glycolato)­cobalt(II)

K₂[Mo₂O₄(C₂O₄)₂(H₂O)₂]·3H₂O

Disodium tetra­kis­(hexanoato-O)zinc(II)

20-Di­cyano­methyl­ene-5,8,11,14-tetraoxa-2,17-di­thia­bicyclo­[16.4.1]­tricosa-1(23),18,21-triene and its mercury(II) dichloride complex

Manganese mercury thio­cyanate (MMTC) glycol mono­methyl ether

Monomeric bis­(2,4-pentane­dionato)­cobalt(II)

(4,4′-Bi­pyridine)di­chloroman­ganese(II), a two-dimensional coordination polymer

cis-[(4R,5R)-4,5-Bis­(amino­methyl)-2,2-di­methyl-1,3-dioxolane-N,N′](malonato-O,O′)­platinum(II), an anticancer agent

The Ni^II, Hg^II and Cu^II complexes of 12-membered-ring mixed-donor macrocycles

(12-Hydroxy­methyl-5,5,7,12,14-penta­methyl-1,4,8,11-tetra­aza­cyclo­tetra­decane-N-acetato-N,N′,N′′,N′′′,O,O′)cobalt(III) chloride perchlorate monohydrate

Tris­(ethyl­enedi­amine-N,N′)cobalt(III) oxalate perchlorate dihydrate

Bis(ferrocenium) bis­[tetra­chloro­antimonate(III)] tri­chloro­antimony(III)

(Piperidine-1-carbodi­thioato-S,S′)bis­(tri­phenylphosphine-P)gold(I)

Diamminebis(2,4,6-tri­bromophenolato-O)copper(II)

Interaction between a di­methyl­amino group and an electron-deficient alkene in ethyl (E)-2-cyano-3-(8-di­methyl­amino-1-naphthyl)­propenoate

1,4,4-Tri­methyl-9-phenyl-8-oxa-9-aza­bicyclo­[3.2.2]­non-6-en-2-one

(E)-2-Methyl-5-(1-naphthyl­methyl)­cinnamic acid

Hydrogen bonds and C—H⋯O interactions in 2,2′-di­methoxybi­phenyl-5,5′-di­methanol at 150 K

Bis(4-nitro­phenyl) di­sulfide at 150 K, a three-dimensional framework built from C—H⋯O hydrogen bonds and aromatic π⋯π stacking interactions

N-Nitrosomelatonin

Two strained hexahelicenophanes

2-(2-Pyridyl­imino)-2H-1,2,4-thia­diazo­lo[2,3-a]­pyridine

Conformational preferences in 2-nitro­phenylthiolates: S-(2-nitro­phenyl) 4-toluene­thio­sulfonate

A second monoclinic polymorph of S-(4-tolyl) 4-toluene­thio­sulfonate at 150 and 293 K

An oxazol-5(4H)-one from benzyl­oxy­carbonyl-(Aib)₄-OH

4-Hydroxy-ONN-az­oxy­benzene

Octa-O-acetyl-β,β-thiotrehalose

Methyl 4-O-β-L-fuco­pyranosyl α-D-gluco­pyranoside hemihydrate

2-(1,3-Di­thian-2-yl)benzaldehyde and N-{2-[2-(1,3-dioxan-2-yl)phen­oxy]­ethyl}phthalimide

Intermolecular interactions and molecular geometry in molecular complexes of N,N-di­methyl­aniline: the 1:1 complex with 1,2,4,5-tetra­cyano­benzene

New limonoids from Harrisonia perforata (Blanco) Merr.

The conversion of a pyrrole trimer derivative into a 4,5,6,7-tetra­hydro-4-(pyrrol-2-yl)indol-7-yl­tosyl­amino­indole

Self-assembly of 2-pivaloyl-6-chloro­pterin

1,4-Bis(2-benzimidazolyl)­benzene

Zwitterionic pyrrolidine-2,2-diylbis(phosphonic acid) at 100, 150 and 293 K

1-tert-Butyl-2-methyl­phospho­lane–borane and its coupling product 2,2′-bis­(1-tert-butyl­phospho­lane–borane)

The oxidized form of nicotin­amide adenine dinucleotide

Rinneite, K₃Na[FeCl₆], at 293, 84 and 9.5 K

Precise X-ray structure determinations of K₃Na[FeCl₆] have been performed at 293, 84 and 9.5 K.

Magnesium sulfate hexahydrate at 120 K

The title structure was redetermined at 120 K, confirming the hydrogen-bond pattern found at room temperature, but showing the librational corrections of bond lengths to be unrealistic. The octahedral coordination of Mg atoms is slightly distorted due to hydrogen bonding.

Potassium barium bis­muth oxide

Crystals of KBa₄Bi₃O have been obtained from melting of the elements. The structure contains Bi₂⁴⁻ dumbbells [Bi—Bi = 3.113 (3) Å] and isolated Bi³⁻ anions coordinated by K and Ba atoms. O atoms lie at the centres of Ba tetrahedra.

Four copper(II) complexes with potentially tetradentate tripodal ligands

The four title Cu^II compounds, namely [Cu(fpy)Cl]ClO₄, [Cu(etpa)Cl][CuCl₄]_1/2, [Cu(mopy)Cl]ClO₄ and [Cu(pipy)Cl]PF₆, where fpy is (2-furyl­methyl)­bis(2-pyridyl­methyl)­amine, etpa is 2-[bis(2-pyridyl­methyl)­amino]ethano­late, mopy is (2-morpholino­ethyl)­bis(2-pyridyl­methyl)­amine and pipy is (2-piperidinyl­ethyl)­bis(2-pyridyl­methyl)­amine, have potentially tetradentate tripodal ligands. In [Cu(fpy)Cl]ClO₄ (shown opposite), the O atom of the furan moiety coordinates weakly to the Cu atom at a distance of 2.750 (3) Å.

Tri­benzyl{η⁵-[2-(p-tolyl)­prop-2-yl]­cyclo­penta­dienyl}­zirconium

The title compound crystallizes from light petroleum with two independent mol­ecules in the asymmetric unit. In both mol­ecules, one of the three benzyl ligands is η²-bonded to the Zr atom, indicated by the smallest Zr—CH₂Ph angle and the consequently relatively short Zr⋯C_ipso distance.

Tris(1,10-phenanthroline-N,N′)chromium(III) triperchlorate hydrate

The structure of the cation in the title compound consists of the Cr atom bonded to the N atoms of the three 1,10-phenanthroline ligands, resulting in a distorted octahedral arrangement with the six Cr—N distances ranging from 2.040 (4) to 2.055 (4) Å. One of the perchlorate anions is disordered and is located around two special positions.

μ-Terephthalato-bis­[bis­(1,10-phenanthroline)copper(I)] diperchlorate

The title compound is a centrosymmetric dimer. The terephthalate moiety acts as a bridging ligand and the phenanthrolines as terminal ligands. The unique Cu atom is coordinated by two O and four N atoms in a distorted octahedral geometry, with Cu—O distances of 1.955 (2) and 2.815 (2) Å, and Cu—N distances of 2.008 (2)–2.216 (2) Å.

cis-Bis­(dicyan­amido)bis­(1,10-phen­anthroline)­manganese(II) and cis-bis­(dicyan­amido)­bis­(1,10-phen­anthro­line)­zinc(II)

The isomorphous title compounds, (I>) and (II>), respectively, are monomeric and show distorted octahedral coordination with the monodentate dicyan­amide ligands in cis positions. In both mol­ecules, the metal–N(phenanthroline) bonds trans to the dicyan­amide ligands are significantly longer than the other two.

(o-Benzo­quinone di­imine-N,N′)di­chlorobis(tri­phenyl­phosphine-P)ruthenium(II) 1.33-methanol 0.33-di­chloro­methane solvate

The Ru atom in the title complex shows an octahedral coordination and a trans arrangement of the tri­phenyl­phosphine ligands. The observed bond lengths indicate a quinone rather than a di­amide form for the o-benzo­quinone di­imine ligand. The complex molecule, in a special position, has crystallographic twofold symmetry.

(Aceto­nitrile-N)(o-benzo­quinone di­imine-N,N′)­chloro-trans-bis­(tri­phenyl­phosphine-P)­ruthenium(II) hexa­fluoro­phosphate 0.25-hydrate

The Ru atom in the title complex shows an octahedral coordination. The Cl⁻ ion and the aceto­nitrile mol­ecule are in the same plane as the o-benzo­quinone di­imine ligand, and the tri­phenyl­phosphine ligands are trans. Bond distances for the benzo­quinone di­imine ring establish a quinone arrangement.

Hexa­aqua­cobalt(II) bis­(4-toluene­sulfonate)

The title compound consists of a hexa­aqua­cobalt(II) cation and 4-toluene­sulfonate anions, with no direct coordination of the anion to cobalt. The Co atom, in an octahedral geometry, is on a centre of inversion. The supramolecular structure consists of parallel layers of cations and anions. The anions are arranged with their sulfonate groups directed towards the cation layer in an alternating fashion and form hydrogen bonds with the water mol­ecules of the cation.

Tri­carbonyl­[(6a,7,8,9,10a-η)-3,3-di­methyl-3H-benzo­[f]­chromene]chromium

The title compound is photochromic. Comparison with related complexes indicates that complexation with tri­carbonyl­chromium has only minor effects on the structure of the chromene.

Dysobinin, a tetranortriterpenoid

Our analysis of the title compound establishes its relative stereochemistry. The planar furan ring is twisted with respect to the steroid D ring and the crystal structure is stabilized by C—H⋯O hydrogen bonds and van der Waals interactions.

Two hydro­chlorides of 7-methyl-3,7,11,17-tetra­aza­bicyclo­[11.3.1]­heptadeca-1(17),13,15-triene

The X-ray structure determinations of the di­hydro­chloride monohydrate, (I>), and the tri­hydro­chloride, (II>), of 7-methyl-3,7,11,17-tetra­aza­bi­cyclo­[11.3.1]­heptadeca-1(17),13,15-triene are reported. Protonation occurs at the secondary amine N atoms in (I>) and at all the three amine N atoms in (II>) to which the Cl⁻ ions are linked via N—H⋯Cl hydrogen bonds.

Di­methyl­phenyl­sulfonium tri­fluoro­methane­sulfonate and methyl­diphenyl­sulfonium tri­fluoro­methane­sulfonate

Sulfonium salts are known as photo acid generators (PAG) and have found a wide range of uses in photo-optical applications. Comparing the cations in the title compounds, (I>) and (II>), respectively, there is no significant effect of the methyl/phenyl substituents on the bonding characteristics of the central S atom. As expected, in both cations, the S—Ph bonds are somewhat shorter than the S—Me bonds and the interactions between cations and anions, in both crystal structures, are similar.

[Tris(4-tolyl)­methyl]­benzene

The crystal structure of the title compound in the monoclinic space group C2/c has a columnar packing arrangement with a 7.20 Å axis, a feature common to several tetra­phenyl­methanes.

1,3-Propane­diammonium bis­(3′-nitro-trans-cinnamate) and trans-1,2-cyclo­hexane­diammonium bis­(3′-nitro-trans-cinnamate)

In the two title adducts, (I>) and (II>), respectively, hydrogen bonds between the di­ammonium and carboxyl­ate ions form a two-dimensional network parallel to the ab plane in (I>) and one-dimensional chains along the c axis in (II>). The cyclohexanedi­ammonium ion in (II>) has a crystallographic twofold axis.

Tris(2-cyano­ethyl)­amine

The title compound adopts a conformation with three cyano­ethyl groups oriented in the same direction, suggesting the compound may behave as a potential tripodal ligand.

Ferroelastic n-butyl­ammonium di­hydrogen­phosphate

n-Butyl­ammonium di­hydrogen phosphate is ferro­elastic. Ferroelastic switching is concomitant with the hopping of some H atoms involved in hydrogen bonds from donor to acceptor O atoms.

3-Acet­oxy­cyclo­hex-4-ene-1,2-di­carboxylic anhydride

The title compound was found to exist as the endo–cis isomer with a pair of enantiomers in the asymmetric unit. The cyclo­hexene ring is folded about the methyl­ene-to-CH(acetoxy) vector to give a boat conformation.

(R)-(+)-2,2′-Bis­(di­phenyl­phosphinoyl)-1,1′-bi­naphthyl

The title compound (BINAP oxide) was synthesized by direct oxidation of (R)-(+)-2,2′-bis­(di­phenyl­phosphino)-1,1′-bi­naphthyl (BINAP) with tert-butyl hydro­peroxide in toluene solution. The angle between the naphthyl planes of the bi­naphthyl group is 94.17 (3)°.

1-(2-Hy­droxy-4,6-di­methyl­phenyl)­ethanone

The air-stable title compound was obtained by heating liquid acetyl­acetone with solid tri­phenyl­bismuth and was recrystallized from benzene. The product has two symmetry-equivalent but essentially identical mol­ecules in the asymmetric unit, both showing an intramolecular O—H⋯O hydrogen bond.

3,5-Di­fluoro-4-nitro­pyridine N-oxide and 3,5-di­amino-4-nitro­pyridine N-oxide monohydrate

In the mol­ecules of the title compounds, (I>) and (II>), respectively, that of (I>) is twisted around the C—NO₂ bond by 38.5 (1)°, while that of (II>) adopts a planar conformation stabilized by intramolecular hydrogen bonds, with a significant redistribution of π electrons.

Di­ethyl 9,10-di­hydro-9,10-ethano­anthracene-11,12-trans-di­carboxyl­ate

The title compound is the product of the Diels–Alder reaction of anthracene with fumaric acid diethyl ester. The molecular C₂ symmetry is nearly fulfilled in the crystal. Only the terminal torsion angles about the O—CH₂ groups show significant differences.

Di­chloro­maleic anhydride

Molecules of the title compound possess approximate non-crystallographic C_2v symmetry, which is broken by the two chlorine substituents deviating from the ring plane. The closest intermolecular contacts are of 2.888 (2) Å between a carbonyl O atom and the C atom of a carbonyl group, forming chains of mol­ecules.

Pyridine-4-carb­aldehyde azine

In the crystal structure of the title compound, the pyridine ring makes a dihedral angle of 1.12 (9)° with the mean plane of the complete almost planar and crystallographically centrosymmetric mol­ecule. There are stacks of parallel mol­ecules along the a-axis direction, with alternate stacks having a herring-bone arrangement relative to each other and an interplanar spacing of 3.551 Å.

3-Acetyl-4-benzoyl-2-methyl-5-phenyl-3,3a-di­hydro­pyrazolo­[2,3-c]pyrimidine-7(6H)-thione

The mol­ecule of the title compound is not planar. The dihedral angle between the two phenyl rings is 27.46 (7)° and in the di­hydro­pyrazolo­pyrimidine ring the total puckering amplitude Q_T is 0.526 (3) Å. The structure is stabilized by both intra- and intermolecular C—H⋯O interactions, and by an intermolecular N—H⋯S hydrogen bond.