A three-dimensional metal–organic polymer: poly[bis­(μ₂-pyrimidine-2-thiol­ato-κ⁴N¹,S:S,N³)lead(II)]

The first complex of Pb^II with the pyrimidine-2-thiol­ate ligand shows a three-dimensional structure. The pyrimidine-2-thiol­ate anions are coordinated in a bridging fashion through both N atoms and the S atom. The net topology is represented by a Shläfli symbol of 6⁶.

A two-dimensional Zn^II coordination polymer constructed from benzene-1,2,3-tri­carb­oxy­lic acid and N,N′-bis­[(pyridin-4-yl)methyl­idene]hydrazine

A new two-dimensional zinc(II) coordination polymer containing Zn₄(OH)₂ secondary building units has been prepared under solvothermal conditions using benzene-1,2,3-tri­carb­oxy­lic acid and N,N′-bis­[(pyridin-4-yl)methyl­idene]hydrazine and it appears to have potential for application as a luminescent material.

Structural studies of (prop-2-en-1-yl)bis­[(pyridin-2-yl)methyl­idene]amine hetero-scorpionate copper complexes

In five copper(I) and copper(II) complexes with (prop-2-en-1-yl)bis­[(pyridin-2-yl)methyl­idene]amine acting as a scorponiate ligand, control over the coordination geometry by modifying the counter-ion and the oxidation state of the copper center was demonstrated.

A three-dimensional Cd^II coordination polymer constructed from 1,1′-bi­phenyl-2,2′,5,5′-tetra­carboxyl­ate and 1,4-bis­(1H-imidazol-1-yl)benzene ligands

A three-dimensional Cd^II coordination polymer, with a (3,4,5)-connected topological network, was assembled from 1,1′-biphenyl-2,2′,5,5′-tetra­carboxyl­ate (bpta⁴⁻) and 1,4-bis­(1H-imidazol-1-yl)benzene ligands, wherein the fully deprotonated bpta⁴⁻ ligand exhibits a new coordination mode. The complex might be a candidate for a thermally stable and solvent-resistant blue fluorescent material.

Structures of Co^II and Zn^II complexes of the proton-transfer compound derived from pyrazine-2,3-di­carb­oxy­lic acid and piperazine

The complexation of the dianion of pyrazine-2,3-di­carb­oxy­lic acid with Co^II and Zn^II has been investigated with the use of piperazinediium as the counter-cation. The structure of the starting proton-transfer reagent is also reported.

Structural study of a manganese(II) `picket-fence' porphyrin complex

The structural investigation of (cryptand-222)potassium chlorido­[meso-tetra­(α,α,α,α-o-pivalamido­phen­yl)porphyrinato]manganese, [K(222)[Mn(TpivPP)Cl], reveals a near-planar conformation of the porphyrin plane, an off-axis tilting of the axial chloride ligand and a noticeable porphyrin core doming.

A one-dimensional Cd^II coordination polymer constructed from 4-(di­methyl­amino)­pyridinium-1-acetate ligands and thio­cyanate coordination bridges

A new cadmium thio­cyanate complex displays two types of Cd^II atoms in distorted octa­hedral coordination environments. Neighbouring Cd^II atoms are linked by thio­cyanate bridges to form a one-dimensional zigzag chain and a one-dimensional coordination polymer. Hydrogen-bond inter­actions are involved in the formation of the supra­molecular network.

Experimental and theoretical studies of the products of addition–elimination reactions between benzil dihydrazone and three isomeric chloro­benz­aldehydes

A series of di-Schiff bases formed between benzil dihydrazone (BDH) and three isomeric chloro­benz­aldehydes were designed and synthesized to be used as model compounds to help to explain the reaction mechanisms for the formation of Schiff bases.

1-(7-Chloro-1,4-di­hydro­quinolin-4-yl­idene)thio­semicarbazide and its hydro­chloride: evidence for the existence of a stable imine tautomer in the solid state of 4-amino­quinoline free bases, an anomalous case in nitro­gen heterocycles

Based on the bond distances and angles, and the unambiguous location of the H atoms, the crystal structures of 1-(7-chloro-1,4-dihydroquinolin-4-ylidene)thiosemicarbazide and its hydrochloride salt reveal the presence of the unusual imine tautomeric form.

Synthesis, structure and characterization of two copper(II) supra­molecular coordination polymers based on a multifunctional ligand 2-amino-4-sulfo­benzoic acid

Two copper(II) supra­molecular coordination polymers based on the multifunctional 2-amino-4-sulfo­benzoic acid ligand have been synthesized and characterized, and show different dehydration–rehydration behaviours.

Synthesis, characterization and crystal structures of the bidentate Schiff base N,N′-bis­(2-nitro­cinnamaldehyde)­ethyl­enedi­amine and its complex with CuNCS and tri­phenyl­phosphane

The Schiff base N,N′-bis­(trans-2-nitro­cinnamaldehyde)­ethyl­enedi­amine has a centrosymmetric mol­ecular structure with significant twists from planarity. In the copper(I) complex, it acts as a bidentate ligand with a flattened gauche conformation for N—C—C—N and a rather bowed shape overall.

New hydro­phobic L-amino acid salts: maleates of L-leucine, L-isoleucine and L-norvaline

Three new maleates of hydro­phobic L-amino acids (L-leucine, L-isoleucine and L-norvaline) are noncentrosymmetric and show an NLO effect. The crystals are promising candidates to be used as substrates for the deposition of thin films of organic mol­ecules. Two of them show inter­esting mechanical behaviour.

Di­cyclo­hexyl­ammonium bromo­acetate: a low mol­ecular mass organogelator with a one-dimensional secondary ammonium mono­carboxyl­ate (SAM) synthon

In the crystal of di­cyclo­hexyl­ammonium bromo­acetate, the anions and cations assemble through N—H⋯O inter­actions to form zigzag chains with the (⋯H—N—H⋯O—C—O⋯)_n motif commonly found in secondary ammonium mono­carboxyl­ate gelator salts. Gelation tests revealed that the salt is capable of gelling DMF and DMSO.

Accidental formation of Gd₄(SiO₄)₂OTe: crystal structure and spectroscopic properties

Gd₄(SiO₄)₂OTe was obtained as an unexpected product while studying the Gd₂Te₃–Cu₂Te system. Excitation and emission spectra were measured using synchrotron radiation and the compound appears to be a promising optical material when doped with rare-earth ions.

Four cocrystals of thymine with phenolic coformers: influence of the coformer on hydrogen bonding

Crystallization of the nucleobase thymine with four phenolic coformers resulted in cocrystal formation. All four structures exhibit thymine–thymine base pairing. The utilization of the donor and acceptor atoms of thymine in the hydrogen bonding is influenced by the coformers.

A chalcone showing positional disorder, two related di­aryl­cyclo­hexenones showing enanti­omeric disorder and a related hy­droxy­terphenyl, all derived from simple carbonyl precursors

A simple reaction pathway to 5′-hy­droxy-1,1′:3′,1′′-terphenyls beginning with simple aldehydes and ketones involves chalcones and di­aryl­cyclo­hexenones as inter­mediates and examples are reported of all three compound types. The chalcone exhibits whole-mol­ecule positional disorder and two di­aryl­cylohexenones both exhibit enanti­omeric disorder.

Hydro­thermal synthesis, crystal structure and photoluminescence of two homochiral zinc(II) coordination polymers

Two homochiral coordination polymers with a two-dimensional layer structure have been obtained. Photoluminescence investigations show that both these compounds display a strong emission in the blue region.

Structure determination of KScS₂, RbScS₂ and KLnS₂ (Ln = Nd, Sm, Tb, Dy, Ho, Er, Tm and Yb) and crystal–chemical discussion

The article deals with the structure determination of some alkali rare-earth sulfides (KScS₂, RbScS₂ and KLnS₂, Ln = Nd, Sm, Tb, Dy, Ho, Er, Tm and Yb) and with the crystal–chemical analysis of different variables such as unit-cell parameters, their ratios, the thicknesses of the S—S layers, sulfur's z-fractional parameters and bond valences.

Synthesis and characterization of (6-{[2-(pyridin-2-yl)hydrazinyl­idene]meth­yl}pyridin-2-yl)methanol: a supra­molecular and topological study

(6-{[2-(Pyridin-2-yl)hydrazinyl­idene]meth­yl}pyridin-2-yl)methanol was synthesized by condensation of 6-(hy­droxy­methyl)­pyridine-2-carbaldehyde with 2-hydrazinyl­pyridine. The three-dimensional supra­molecular structure is formed by N—H⋯N and O—H⋯N hydrogen bonds and weak C—H⋯C inter­actions, and these were qu­anti­fied by the Hirshfeld surface method.

Synthesis, structure and luminescence properties of two new acyl­amide metal–organic frameworks showing 4-connected CdSO₄ and a threefold inter­penetrating dia net

In two new acyl­amide metal–organic frameworks (MOFs), based on mixed N- and O-donor ligands, the Zn^II complex is a 4-connected CdSO₄ net with no inter­penetration, and the Cd^II complex is a 4-connected dia net with threefold inter­penetration.