Neutral 4-phenyl-1-[phen­yl(pyridin-2-yl)methyl­idene]semicarbazide and its salt forms with inorganic anions

The compound 4-phenyl-1-[phen­yl(pyridin-2-yl)methyl­idene]semicarbazide crystallized as the E isomer due to the existence of weak π–π inter­actions between pairs of mol­ecules. Its inorganic salts also crystallized as the E isomers, influenced by the establishment of hydrogen bonds involving the N—H groups of the cation and the water mol­ecules and counter-ions (chloride, nitrate or thio­cyanate). The calculated IR spectrum of the hydrated cation is in good agreement with the experimental results.

A three-dimensional Zn^II coordination network based on 5,5′-methyl­enebis(2,4,6-tri­methyl­iso­phthalic acid) and 2,7-bis­(1H-imidazol-1-yl)fluorene: synthesis, structure and luminescence properties

A new two-dimensional coordination polymer based on 5,5′-methyl­enebis(2,4,6-tri­methyl­isophthalic acid) and 2,7-bis­(1H-imidazol-1-yl)fluorene has been prepared and structurally characterized.

Inclusion complex of β-cyclo­dextrin with coffee chloro­genic acid: new insights from a combined crystallographic and theoretical study

The [4]pseudorotaxane of β-cyclo­dextrin (β-CD) with coffee chloro­genic acid (CGA) is reported for the first time in CD inclusion complexes. The atomistic and thermodynamic insights of the trimodal and dimeric β-CD–CGA inclusion complexes are gained through single-crystal X-ray diffraction combined with DFT calculations.

The surprising pairing of 2-amino­imidazo[1,2-a][1,3,5]triazin-4-one, a component of an expanded DNA alphabet

The crystal structure of a heterocyclic mol­ecule that exhibits an acceptor–acceptor–donor hydrogen-bonding pattern is reported, namely 2-amino­imidazo[1,2-a][1,3,5]triazin-4(3H)-one (trivially named P). P is part of an `artificially expanded genetic information system' (AEGIS). The crystal structure shows two tautomers of P packed in a Watson–Crick fashion cocrystallized in a 1:1 ratio.

An aceto­nitrile-solvated cocrystal of piroxicam and succinic acid with co-existing zwitterionic and non-ionized piroxicam mol­ecules

This work reports a new aceto­nitrile-solvated cocrystal of piroxicam (PRX) and succinic acid (SA). The outcome of crystallization from aceto­nitrile can be controlled by varying only the PRX:SA ratio, with a higher PRX:SA ratio in solution unexpectedly favouring a lower stoichiometric ratio in the solid product.

Four isostructural lanthanide(III) coordination compounds based on a new N-oxydic pyridyl naphthalenedi­imide ligand: synthesis and characterization

Four novel isostructural lanthanide(III) coordination polymers based on a novel N-oxydic pyridyl naphthalenedi­imide ligand were synthesized and their crystal structures analysed. One of them demonstrates potential as an indirect band gap semiconductor material.

Structure and electrostatic properties of the pyrimethamine–3,5-di­hydroxy­benzoic acid cocrystal in water solvent studied using transferred electron-density parameters

The electron-density-derived properties of the cocrystal of an anti­malarial drug were studied using X-ray diffraction data collected at room temperature.

Energetic propane-1,3-diaminium and butane-1,4-diaminium salts of N,N′-di­nitro­ethyl­enedi­aza­nide: syntheses, crystal structures and thermal properties

Two novel energetic salts of ethyl­enedinitramine (EDNA) with alkanedi­amines have been crystallized and analyzed for their thermal properties. The extensive hydrogen-bonding networks in the energetic salts serve to improve their friction and shock sensitivity.

A quarter of a century after its synthesis and with >200 papers based on its use, `Co(CO₃)_0.5(OH)·0.11H₂O′ proves to be Co₆(CO₃)₂(OH)₈·H₂O from synchrotron powder diffraction data

The crystal structure of Co₆(CO₃)₂(OH)₈·H₂O was solved ab initio and refined from synchrotron powder diffraction data.

Synthesis and crystal structures of some bis­(3-methyl-1H-indol-2-yl)(salic­yl)methanes

Four 2,2′-bis­indolyl­methanes (BIMs) were synthesized and two were characterized crystallographically. These compounds show remarkably similar hydrogen-bonding motifs in the solid state.

Hypervalent organoselenium compounds stabilized by intra­molecular coordination: synthesis and crystal structures

In the structures of two chalcogena­penta­lene derivatives, 6-phenyl-6,7-di­hydro-5H-2,3-dioxa-2aλ⁴-selena­cyclo­penta­[hi]indene and 5-phenyl-5,6-di­hydro-4H-benzo[c][1,2]oxa­selenole-7-carbaldehyde, the former is stabilized by Se—O bonds, while in the latter, there is both an Se—Se bond and an Se⋯O inter­action, which helps in the stabilization of the structure.

Two single-enanti­omer amido­phospho­esters: a database study on the chirality of (O)₂P(O)(N)-based structures

The statistically identical chiral architectures constructed from N—H⋯O and C—H⋯O hydrogen bonds are discussed for a pair of optical isomers belonging to the amido­phospho­ester family.

A Guide to the Elements