Role of weak C—H⋯O and strong N—H⋯O inter­molecular inter­actions on the high-symmetry mol­ecular packing of trans-cyclo­hexane-1,4-dicarboxamide

An unpredicted fourfold screw N—H⋯O hydrogen bond C(4) motif in the primary dicarboxamide trans-cyclo­hexane-1,4-dicarboxamide was investigated by single-crystal X-ray diffraction and IR and Raman spectroscopies. Based on the results, a structural model is proposed which helps to rationalize the unusual fourfold screw mol­ecular arrangement.

Crystal structure of the thortveitite-related M phase, (Mn_xZn_1–x)₂V₂O₇ (0.75 < x < 0.913): a combined synchrotron powder and single-crystal X-ray study

The crystal structure of the M phase, (Mn_xZn_1–x)₂V₂O₇ (0.75 < x < 0.913), can be described as a distortion of the thortveitite-type crystal structure of β-Mn₂V₂O₇. The distortions which give rise to the M phase from the β-Mn₂V₂O₇ prototype are noticeably less pronounced than the distortions introduced when β-Mn₂V₂O₇ transforms at low temperature to α-Mn₂V₂O₇. A twofold superstructure in the diffraction patterns of crystals of the M phase used for single-crystal X-ray diffraction work arises from twinning by reticular pseudomerohedry.

The new heteropolyoxometalate compound (C₆H₈N)₅[HAs₂Mo₆O₂₆(H₂O)]·3H₂O: crystal structure and Hirshfeld surface analysis

The heteropolyoxometalate compound (C₆H₈N)₅[HAs₂Mo₆O₂₆(H₂O)]·3H₂O contains a new [HAs₂Mo₆O₂₆(H₂O)]⁵⁻ polyanion. Crystallographic analysis provided an understanding of the architecture and structural features of the complex crystal lattice and Hirshfeld surface analysis shed more light on the inter­molecular inter­actions occurring in the crystal.

Eight Schiff bases derived from various salicyl­aldehydes: phenol–imine and keto–amine forms, conformational disorder, and supra­molecular assembly in one and two dimensions

The structures of eight Schiff bases derived from various salicyl­aldehydes are reported: five of them are new and three are re-investigations of previously reported examples. Of the eight, six adopt the phenol–imine constitution and the other two adopt the keto–amine form; two of the phenol–imine examples exhibit conformational disorder.

Different coordination modes of trans-2-{[(2-meth­oxy­phen­yl)imino]­meth­yl}phenoxide in rare-earth complexes: influence of the metal cation radius and the number of ligands on steric congestion and ligand coordination modes

Structures of 2-{[(2-meth­oxy­phen­yl)imino]­meth­yl}phenoxide complexes of rare-earth metals are controlled by steric congestion influenced by the rare-earth ionic radius, leading to three different coordination modes of the ligand.

Synthesis of Re^I tri­carbonyl complexes with various sulfur- and oxygen-donating ligands: crystal structures of two Re^I dinuclear structures bridged by S atoms

The structures of two dinuclear Re^I complexes are reported, one with a 2,2′-sulfanediyldi(ethanethiol­ate) bridging ligand and the other with three 2-meth­oxy­benzene­thiol­ate bridging ligands. Two mononuclear Re^I complexes have also been characterized by spectral methods.

A new two-dimensional Co^II coordination polymer based on bis­[4-(2-methyl-1H-imidazol-1-yl)phen­yl] ether and bi­phenyl-4,4′-diyldi­carb­oxy­lic acid: synthesis, crystal structure and photocatalytic degradation activity

A cobalt(II) compound, prepared by the reaction of Co(NO₃)₂·6H₂O with biphenyl-4,4′-diyldi­carb­oxy­lic acid and bis­[4-(2-methyl-1H-imidazol-1-yl)phen­yl] ether in a mixture of H₂O and di­methyl­formamide, possesses an achiral two-dimensional layer based on opposite-handed helical chains and exhibits highly photocatalytic degradation activity for the degradation of methyl­ene blue at room temperature.

A new one-dimensional Cd^II coordination polymer incorporating 2,2′-(1,2-phenyl­ene)bis­(1H-imidazole-4,5-di­carboxyl­ate)

A new Cd^II coordination polymer based on 2,2′-(1,2-phenyl­ene)bis­(1H-imidazole-4,5-di­carb­oxy­lic acid) has been prepared and structurally characterized. The polymer exhibits a one-dimensional structure, in which H₂Phbidc⁴⁻ anions coordinate to Cd^II ions in an octa­dentate mode.

A new Zn^II coordination polymer based on 4-(pyridin-4-yl)benzoic and formic acids: in-situ synthesis, crystal structure and luminescence properties

Poly[(μ₂-formato)[μ₂-4-(pyridin-4-yl)benzoato]zinc(II)] contains two independent structural units in the asymmetric unit, forming two similar two-dimensional (2D) layer structures. These similar 2D layers are arranged alternately and are linked with each other by dense C—H⋯O hydrogen bonds to generate a three-dimensional supra­molecular framework.

Synthesis, crystal structure and cytotoxic activity of novel 5-methyl-4-thio­pyrimidine derivatives

The cytotoxicities of 4-thio­pyrimidine derivatives obtained from ethyl 4-methyl-2-phenyl-6-sulfanyl­pyrimidine-5-carboxyl­ate were examined against Human umbilical vein endothelial cells (HUVEC) and HeLa, K562 and CFPAC cancer cell lines. The presence of hy­droxy­methyl and methyl groups offers an inter­esting new insight into the structures and behaviour of these derivatives.

Syntheses, crystal structures and optical properties of two one-dimensional germanophosphates: HRb₃Ge₂(HPO₄)₆ and CsGe(HPO₄)₂(OH)

Two one-dimensional alkali-metal germanophosphates (GePOs), namely, HRb₃Ge₂(HPO₄)₆ and CsGe(HPO₄)₂(OH), have been prepared by the solvothermal method. The former shows one-dimensional (1D) [Ge(HPO₄)₆]_∞ chains along the c axis and the latter shows 1D [Ge(HPO₄)₄(OH)₂]_∞ chains.

Crystal structure and sequential dehydration transitions of disodium guanosine 5′-monophos­phate tetra­hydrate

It was found that the structure of disodium guanosine 5′-monophosphate tetra­hydrate differs markedly from that of the hepta­hydrate, but greatly resembles that of disodium de­oxy­guanosine 5′-monophosphate tetra­hydrate.

Dilithium (citrate) crystals and their relatives

The crystal structures of four isostructural citrate salts, LiMHC₆H₅O₇ (M = Li, Na, K and Rb), have been solved and refined using laboratory powder X-ray diffraction data and optimized using density functional techniques.

Synthesis, crystal structures and anti-inflammatory activity of four 3,5-bis­(aryl­idene)-N-benzene­sulfonyl-4-piperidone derivatives

Four 3,5-bis­(aryl­idene)-N-benzene­sulfonyl-4-piperidone derivatives were synthesized and their structures were confirmed by single-crystal X-ray diffraction. Preliminary evaluations were conducted on their anti-inflammatory activity by evaluating their inhibitory effects on LPS-induced IL-6 and TNF-α secretion.