The structures of three doubly-acyl­ated 4-amino­anti­pyrine com­pounds where the aryl substituent is varied are reported and analysed in terms of their relative conformation, inter­molecular inter­actions and overall packing. The com­pounds were crystallized using the encapsulated nanodroplet crystallization (ENaCt) protocol.

Three pyridine-based halide-bibridged polymers have been synthesized and their structures determined. The effect of the size of the halides on the crystal structures has been investigated.

The crystal structure of a reagent frequently used for the preparation of buffer solutions is reported, showing that the mol­ecule lies on a crystallographic mirror plane, and has a bent conformation.

The title compound is a hydrated, partially protected derivative of d-gluco­pyran­ose. Inter­molecular inter­actions connect the entities of the asymmetric unit to a three-dimensional network.

A one-dimensional lanthanum coordination polymer based on 3,6-di­chloro­phthalate has been prepared by microwaves-assisted synthesis and structurally described.

X-ray crystal structures of glycosyltransferase C from the Limosilactobacillus reuteri 100-23 (LrGtfC100-23) accessory secretion system were determined in its apo form and in complexes with UDP and with UDP-N-acetylglucosamine, which revealed candidate residues involved in strain-specific recognition of UDP-sugars. Site-directed mutagenesis of these residues led to a switch of the UDP-sugar binding specificities of LrGtfC100-23 and the highly homologous LrGtfC from L. reuteri ATCC 53608.

The lithium halide dimethyl ether (DME) adducts [Li2Cl2(DME)4] and [Li2Br2(DME)4] form dimeric units linked into layers by CH3⋯Cl tetrel bonds or CH3⋯CH3, CH3⋯O and CH3⋯Br contacts, illustrating the coordination ability of dimethyl ether and its role in directing supra­molecular assembly.

In the title compound, the dihedral angle between the planes of the pyridine and oxo­pyrroli­dine rings is 6.9 (2)°. In the crystal, inversion dimers linked by pairwise N—H⋯O hydrogen bonds generate R22(14) loops.

The extended structure of the title compound features strong N—H⋯N hydrogen bonds forming infinite C(4) chains propagating along the c-axis direction.

In the title compound, C14H14O4, the dihedral angle between the coumarin nucleus and the penta­noate moiety is 84.6 (9)°. In the crystal, mol­ecules are linked by C—H⋯O hydrogen bonds into centrosymmetric dimers with an R22(8) graph-set motif, and π–π inter­actions are also observed.

The phenyl ring forms a dihedral angle of 34.72 (6)° with the mean plane of the pyrazolo­[3,4-d]pyrimidine ring system.

The crystal structure of (C6H14N2)[Br3]2 contains diprotonated tri­ethyl­enediaminium cations, the charge of which is com­pensated by [Br3]− anions. The crystal packing is stabilized by Br⋯Br contacts, forming two-dimensional layers, and by N—H⋯Br/C—H⋯Br inter­actions between cations and tribromide anions.

In the title compounds, 2,2′-{[anthracene-9,10-diylbis(methyl­ene)]bis­(sulfanedi­yl)}di­benzoic acid di­methyl­acetamide tetra­solvate, C30H22O4S2·4C4H9NO 1 and 4,4′-{[anthracene-9,10-diylbis(methyl­ene)]bis­(­oxy)}di­benzoic acid di­methyl­formamide disolvate, C30H22O6·2C3H7NO 2, the complete anthracene–benzoic acid mol­ecule is generated by a crystallographic centre of symmetry. The dihedral angle between the anthracene ring system and the pendant ring is 71.43 (7) in 1 and 75.27 (12)° in 2. In the extended structures of both compounds, O—H⋯O hydrogen bonds link the main mol­ecules into pairs of solvent mol­ecules to generate trimers.

In the title compound, the six-membered ring is disordered over two half-chair orientations. In the crystal, infinite [001] chains linked by N—H⋯N hydrogen bonds occur.

The compound is a neutral discrete complex where the silver(I) center is coordinated by three phospho­rus atoms from three distinct PTA ligands and one carbon atom from the nitrile ion, resulting in a distorted tetra­hedral geometry around the Ag centre.

A trinuclear copper(II)–levofloxacin complex, (C18H22FN3O4)2[Cu3Cl9(H2O)2]Cl, was synthesized and its crystal structure determined. It features five-coordinated CuII centres with Jahn–Teller distortion and a three-dimensional hydrogen-bonded supra­molecular network.

The crystal structure of the metastable form of S-ibu­pro­fen–nicotinamide cocrystals was solved from powder X-ray diffraction data and explains the main mechanisms responsible for the relative stability of the two forms of the cocrystals. This also made it possible to explain the transition mechanism between the two forms with tem­per­a­ture.

The performance of the Hirshfeld atom refinement (HAR) and transferable aspherical atom model (TAAM) approaches in crystal structure refinement and the determination of the nature of chemical bonds is com­pared for a series of quinone-like com­pounds, known for single–double bond alternation. The HAR approach is shown to adequately reproduce the bond alternation in the electron-density distribution, while the TAAM approach does not perform as well in such specific cases.

The title compound crystallizes in ortho­rhom­bic space group Pnma with both cations and anions lying on a mirror plane in the crystal. Parallel mol­ecules form stacks with inter­planar spacing 3.1473 (2) Å, but slipped by 1.97 Å.

The polymorphism of the title salen-type compound synthesized from racemic-(+/-)-1,2-di­phenyl­ethyl­enedi­amine and 3-chloro­salicyl­aldehyde is reported

The title mol­ecular salt, C23H21N2+·C6H2N3O7−, featuring discrete ion pairs, crystallizes from ethanol through slow solvent evaporation. In the crystal, the imidazolium cation and the picrate anion are linked by N—H⋯O hydrogen bonds as a result of proton transfer from picric acid to the pyrimidine-type nitro­gen atom of the imidazole ring.

A μ-oxo vanadium(V) dimeric complex, μ-oxido-bis­[(2,2′-{[ethane-1,2-diylbis(aza­nedi­yl)]bis­(methyl­ene)}diphenolato)oxidovanadium(V)], was synthesized and structurally characterized.