A survey of inter­actions in crystal structures of pyrazine-based compounds

This review highlights different aspects of the pyrazine ligand and its derivatives for the construction of metal complexes having multinuclear structures.

A half-sandwich Ta^V di­chlorido complex containing an O,N,O′-tridentate Schiff base ligand: synthesis, crystal structure and in vitro cytotoxicity

A new half-sandwich tantalum(V) dichlorido complex containing the O,N,O′-tridentate double-deprotonated 2-eth­oxy-6-{(E)-[(2-oxido­phen­yl)imino]­meth­yl}phenolate ligand was prepared, thoroughly characterized and revealed considerable in vitro cytotoxicity against the A2780 human ovarian carcinoma cell line.

First crystal structures of metal complexes with a 4-nitro­pyrazole-3-carb­oxy­lic acid ligand and the third crystal form of the ligand

The title structures represent rare examples of metal complexes comprising a 3,4-disubstituted pyrazole derivative as a bridging ligand and the first crystal structures of metal complexes with a 4-nitro­pyrazole-3-carb­oxy­lic acid-based ligand.

Polymorphic crystals of oxacalix[4]arene with 1,3-alternate conformations of S₄ and C₂ symmetry

Calix[4]arene and oxacalix[4]arene derivatives have eight possible conformations in the up and down directions of their four aromatic rings from the mean plane of a bridged central ring, the conformations of which determine the functionality of the host frameworks.

The structure of the anti-aging agent J147 used for treating Alzheimer's disease

The mol­ecular structure of J147 has been determined at 150 K and corresponds to the minimum-energy conformation in the gas phase calculated by DFT. 15 other conformations have been calculated and compared with the minimum.

Synthesis, crystal structure and photoluminescence of a three-dimensional zinc coordination compound with NBO-type topology

A three-dimensional NBO-type topological metal–organic framework (MOF) formed from zinc(II) and para-terphenyl-3,3′,5,5′-tetra­carboxyl­ate was synthesized by solvothermal reaction.

The typical crystal structures of a few representative α-aryl-α-hy­droxy­phospho­nates

The crystal structures of seven α-aryl-α-hy­droxy­phospho­nates synthesized by the Pudovik reaction of substituted benzaldehydes and dialkyl phosphites were studied to gain a better understanding of the organization in this type of mol­ecule in the solid state. The crystal structures show a balance between the C—OH⋯O=P chain-linked packing and the dimeric types of hydrogen-bond bridges of inter­molecular pairs of such functions.

Crystal structure, shape analysis and bioactivity of new Li^I, Na^I and Mg^II complexes with 1,10-phen­anthroline and 2-(3,4-di­chloro­phen­yl)acetic acid

Reactions of 1,10-phenanthroline (phen) and 2-(3,4-di­chloro­phen­yl)acetic acid (dcaH) with M_n(CO₃) (M = Li^I, Na^I and Mg^II; n = 1 and 2) in MeOH yield the mononuclear lithium complex, the dinuclear sodium complex and the one-dimensional chain magnesium complex. In these complexes, phen binds via an N,N′-chelate pocket, while the deprotonated dca⁻ ligands coordinate either in a monodentate or bidentate fashion.

Crystallographic identification of a series of manganese porphyrin complexes with nitro­genous bases

Syntheses, crystal and mol­ecular structures, and binding constants are reported for four manganese(III) porphyrin complexes.

Concomitant cocrystal and salt: no inter­conversion in the solid state

A cocrystal and a mol­ecular salt of β-alanine and DL-tartaric acid do not inter­convert in the solid state over a wide temperature range, though such a transformation can be solvent-mediated.

Structural studies and anti­leishmanial activity of 2-acetyl­pyridine and 2-benzoyl­pyridine nitro­imidazole-derived hydrazones

Three imidazole hydrazone compounds were prepared and characterized. The compounds proved not to be cytotoxic to J774.A1 macrophage cells. Two of the hydrazones exhibited activity against Leishmania chagasi, whereas the third was inactive. The presence of a 4-nitro group probably favours anti­leishmanial activity over the 2-nitro group.

Hydrogen bonding in two benzene-1,2-diaminium pyridine-2-carboxyl­ate salts and a cocrystal of benzene-1,2-di­amine and benzoic acid

The isostructural salts benzene-1,2-diaminium bis(pyridine-2-carboxyl­ate), 4,5-di­methyl­benzene-1,2-diaminium bis(pyridine-2-carboxyl­ate) and the 1:2 benzene-1,2-di­amine–benzoic acid cocrystal are reported. Hydrogen-bonding, π–π, and C—H⋯π inter­actions are explored.

Isolation and structure of an 18-membered macrocycle containing two diselenide linkages and its precursor

The structures of an 18-membered aza­macrocycle containing two disselenide linkages and its precusor are reported.

Hydrogen and halogen bonding in the haloetherification products in chalcone

The reaction of 3-(3,5-di-tert-butyl-4-hy­droxy­phen­yl)-1-phenyl­prop-2-en-1-one with HCl or HBr in MeOH of EtOH leads to the haloetherification products 3-(3-tert-butyl-5-halo-4-hy­droxy­phen­yl)-2-halo-3-alk­oxy-1-phenyl­propan-1-ones. Both inter­molecular hydrogen and halogen bonds were found in the crystal structures of the haloetherification products of chalcone.

Hydrogen bonding and π–π inter­actions in the cocrystal salt [Fe(bpe)₂(H₂O)₄](TCEP)₂·2(bpe) [bpe is trans-1,2-bis­(pyridin-4-yl)ethene and TCEP is 1,1,3,3-tetra­cyano-2-eth­oxy­propenide]

The solid-state structure of the cocrystal salt tetra­aqua­bis­[trans-1,2-bis­(pyridin-4-yl)ethene]iron(II) bis(1,1,3,3-tetra­cyano-2-eth­oxy­propenide)–trans-1,2-bis­(pyridin-4-yl)ethene (1/2) is reported. Density functional theory is used to explore the strengths of the observed O—H⋯N hydrogen bonding and π–π inter­molecular inter­actions.

A two-dimensional organic–inorganic hybrid perovskite-type semiconductor: poly[(2-azaniumyl­ethyl)tri­methylphosphanium [tetra-μ-bromido-plumbate(II)]]

A twisted 2D layered anion structure is formed because of the infiltration of cations and the presence of hydrogen bonds. A band gap of ∼2.700 eV was found through experimental and theoretical studies.

Catalyst- and solvent-free synthesis of 2-fluoro-N-(3-methyl­sulfanyl-1H-1,2,4-triazol-5-yl)benzamide through a microwave-assisted Fries rearrangement: X-ray structural and theoretical studies

A catalyst- and solvent-free approach for the regioselective synthesis of 2-fluoro-N-(3-methyl­sulfanyl-1H-1,2,4-triazol-5-yl)benzamide through a microwave-assisted Fries rearrangement of (5-amino-3-methyl­sulfanyl-1H-1,2,4-triazol-1-yl)(2-fluoro­phen­yl)methanone is provided. The structures of the synthesized amides, tautomerism and the mechanistic pathway were determined by X-ray structure and theoretical studies.

A fourfold inter­penetrating cadmium(II) metal–organic framework based on 2,4,6-tris­(pyri­din-4-yl)-1,3,5-triazine with reversible photochromic properties

A fourfold inter­penetrating cadmium(II) metal–organic framework, which has been prepared using the 2,4,6-tris­(pyridin-4-yl)-1,3,5-triazine ligand, exhibits prominent photochromic behaviour upon UV–Vis light irradiation.