The crystal structure of a polymorph of N′-[(4-hy­droxy­phen­yl)methyl­idene]pyridine-4-carbohydrazide reveals a distinct supra­molecular arrangement arising from variations in inter­molecular hydrogen bonding relative to the known polymorph.

In the title ferrocenylphenyl functionalized imidazolium salt, the 1-(4-ferrocenylphen­yl)-3-(4-nitro­benz­yl)imidazolium cation adopts a syn-periplanar arrangement, with the ferrocenylphenyl substituent tilted by 38.32 (7)° relative to the imidazolium core. In the crystal, inter­ionic C—H⋯F hydrogen bonds generate graph-set motifs R12(7) and R21(4), assembling the ions into chains that propagate along the c-axis direction.

In the title compound, which was synthesized via a four-component Debus–Radziszewski reaction, the OH group of the vanillin substituent forms both an intra­molecular and an inter­molecular hydrogen bond, the latter generating [010] chains. The extended structure is consolidated by weak C—H⋯O and C—H⋯π inter­actions, generating a criss-cross motif.

The Al8.77Fe0.80Ni1.20Si0.23 (aluminium iron nickel silicate) phase, obtained via high-pressure sinter­ing of an Al-rich prealloy (nominal composition Al78.08Fe8.65Ni8.69Si4.58), is characterized as a novel phase in the Al—Si—Ni—Fe quaternary system.

In the title compound, the porphyrin macrocycle is essentially planar, with the Zn atom located in the plane on an inversion centre. The bi­pyridine units are located on both sides of the porphyrin plane due to the substitution at the 3- and 5-positions of the meso-phenyl ring. One bi­pyridine moiety folds back towards the porphyrin, while the other extends away from the porphyrin.

The crystal structure of the title imidazolium salt exhibits structure-directing, inter­molecular halogen-bonding patterns through F⋯Br and F⋯πphen­yl inter­actions via the tetra­fluoro­borate anion.

The title compound crystallizes in space group Pbca with four mol­ecules in the unit cell.

The title compound crystallizes in the monoclinic space group I2/a with one half-mol­ecule in the asymmetric unit. The structure exhibits non-planar Schiff base moieties, extended π-conjugation, and a supra­molecular framework consolidated by C—H⋯O, π–π stacking, and C—H⋯π inter­actions forming layers parallel to the (101) plane.

Single crystals of tri­benzyl­tin(IV) iodide, prepared from hexa­benzyl­distannoxane, Bz3SnOSnBz3, and hydro­iodic acid, have been characterized by single-crystal X-ray diffraction in order to clarify some inconsistencies in the original structure determination. In particular, the present study provides a significantly longer tin–iodide distance, which corresponds much better with those in related structural studies.

Two chlorido and two chelating pyridinyl­imino­benzoic acid ligands coordinate a cobalt(II) centre with the carb­oxy­lic being non-coordinating.

Re-refinement of [Nd2(SO4)3(H2O)4] led to higher precision and accuracy of the structure model, including localization of all H atoms.

In the title ZnII complex, the 1,3-bis­(di­methyl­silyl-3-pyridine)­propane ligands bind to two ZnII ions in a horse-shoe fashion to form a centrosymmetric dimeric 24-membered macrocycle, which further assembles into a supra­molecular structure via weak I⋯H inter­actions.

The IrI atom is coordinated by a bidentate cyclo­octa-1,5-diene (COD) ligand and two N-heterocyclic carbene ligands, leading to a distorted square-planar coordination environment.

In the title compound, the 4H-pyran ring adopts a boat conformation. The dihedral angle between the phenyl and pyran rings is 87.8 (18)°. In the crystal, mol­ecules are linked by N—H⋯O and N—-H⋯N hydrogen bonds.

The coordination number of the central EuIII ion is 8, defined by three bidentate β-diketonato ligands, an aqua ligand and an ethanol ligand.

Corrigendum to IUCrData (2018), 3, x180443.

Crystallographic data for the title compound, C21H16N4, are reported herein. The compound was recrystallized from a methanol/aceto­nitrile solvent system at 298 K. It crystallizes in the Pca21 space group at 100 K and displays inter­molecular hydrogen bonding, through N—H⋯N contacts, and π–π inter­actions.

The mol­ecule of the title compound is nearly planar. In the crystal, the packing of mol­ecules is mainly ensured by N—H⋯O hydrogen bonds, which form R22 (8) graph-set motifs.

Mol­ecules of the title compound, C10H16N2OSe, adopt a chair conformation and are connected via hydrogen bonds into centrosymmetric dimers. C—H⋯O hydrogen bonds inter­connect the dimers.

A 1,2,4,5-tetra-substituted imidazole compound containing pyrole, 4-bromo­phenyl and phenyl groups has been synthesized in a four-component Debus–Radziszewski reaction of 1,2-diketone, aromatic aldehyde, aromatic amine and ammonium acetate

In the title compound, the dihedral angles between the chloro­benzene ring and the acetamide and acetate planes are 40.70 (8) and 88.07 (8)°, respectively; the acetamide and acetate planes make a dihedral angle of 51.39 (9)°. In the extended structure, the mol­ecules are linked by N—H⋯O hydrogen bonds involving the acetamide group, forming C(4) chains propagating along the [010] direction.

The title compound contains three mol­ecules in the asymmetric unit linked by numerous hydrogen bonds.

A third isomer of cyclooctenobis-1,2,3-selenadiazoles is reported. The mol­ecule is located on a twofold rotation axis and the eight-membered ring adopts a twist-chair conformation with planar heterocycles.

Sr2Cu(OH)4(C2O4) is made up from edge-sharing {SrO4(OH)4} polyhedra decorated by {Cu(OH)4} units and oxalate groups.

The monoclinic unit cell of the title compound contains four mol­ecules, two A and two B. In the extended structure, the two similar conformers are connected into A-ribbons and B-ribbons. Three hydrogen bonds connect the mol­ecules within the ribbons, while π–π inter­actions between the phenyl and tetra­zole moieties of different mol­ecules connect the A and B strands; the aromatic rings are nearly coplanar.

The title compound, which exhibits disorder over the terminal tri­fluoro­methyl and methyl entities, is close to planar with the r.m.s. deviation for the non-H/-F atoms being 0.038 Å. In the crystal, the mol­ecules are linked by N—H⋯N inter­actions into a [010] chain with a C11(3) motif.

The title compound crystallizes with two zwitterionic mol­ecules (A and B) in the asymmetric unit, each featuring an intra­molecular N—H⋯O hydrogen bond. In the extended structure, A + A and B + B carb­oxy­lic-acid inversion dimers linked by pairwise O—H⋯O hydrogen bonds arise, which generate R22(8) loops in each case. The dimers are linked by weak C—H⋯π and π–π stacking inter­actions.

In the complex anion of the title salt, the Hg2+ ion is coordinated by four Cl− ligands, forming a distorted tetra­hedral geometry. In the extended structure, the cations and anions are linked via N—H⋯Cl and C—H⋯Cl hydrogen bonds.

In the title compound, the seven-membered 1,3-dithiepane ring adopts a distorted chair conformation. In the extended structure, inversion dimers linked by pairwise C—H⋯O hydrogen bonds generate R22(14) loops.

In the title compound, the dihedral angles between the central isoxazole ring and the 4-fluoro­phenyl and pyridine rings are 37.51 (10) and 12.11 (15)°, respectively.

In this Schiff base derived from tert-butyl­amine and para-nitro­benzaldehyde, C—H⋯O contacts connect the mol­ecules into chains along the b-axis direction.

The title compound features a diquinane being annulated to a cyclo­octene in twist-boat-chair conformation. In the crystal, hydrogen bonds connect the mol­ecules into centrosymmetric dimers, which are further connected into chains.

The title compound, C21H22N2O6S, which was obtained during a study directed to the synthesis of the anti-cancer natural product, pancratistatin, crystallizes with two independent mol­ecules in the asymmetric unit with similar but not identical shapes. The crystal structure confirms the expected mol­ecular structure of the compound.

The refractory high-entropy alloy Mo0.20Nb0.21Ta0.19V0.20W0.20 crystallizes in a tungsten-type structure with all elements located on a single crystallographic site.

The crystal structure and Hirshfeld analysis of the title compound is reported. The E isomer of the central alkene entity was unequivocally determined, in which weak intra­molecular inter­actions between the ketone and the phenyl groups are suggested. In addition, the mol­ecules are connected by weak inter­molecular Cl⋯O inter­actions along [100].

The title compound is the hydro­chloride salt of the ethyl ester of l-valine. Inter­molecular inter­actions connect the entities of the asymmetric unit into sheets lying parallel the the bc plane.

The title compound contains zigzag polymeric chains built up from nine-coordinated DyIII centers and bridging 5-az­an­ium­yl­isophthalate ligands.

The title compound is the acetal of 4-chloro­benzaldehyde and 1,3-propane­diol. In the crystal, weak C—H⋯O contacts connect the mol­ecules to centrosymmetric dimers.

The title compound forms strands along the b-axis direction via hydrogen bonds from the tolyl group to the sulfonyl oxygen atoms. The tricyclic framework is almost planar and the two six-membered aromatic substituents are nearly coparallel.

The ZnII atom in the title compound has distorted octa­hedral N2O4 coordination geometry. The inter­molecular inter­actions in the crystal structure consist of O–H⋯O and weak C–H⋯O hydrogen bonds.

The title quaternary inter­metallic material is a new γ-brass obtained using a high-pressure sinter­ing process.

In the title compound, the dihedral angle between the 2H-chromen-2-one moiety and the C—CO2 ester grouping is 54.30 (5)°. In the crystal, the mol­ecules are linked by C—H⋯O hydrogen bonds forming C(6) [100] chains.

The title compound, C21H38N+·Br−·H2O, is the bromide salt of a quarternary pyridinium cation bearing a hexa­decyl chain on the nitro­gen atom. One mol­ecule of solvent water is present in the asymmetric unit. Classical hydrogen bonds of the O—H⋯Br type are observed next to C—H⋯Br and C—H⋯O contacts that connect the entities of the title compound to sheets parallel to the ab plane.

In the title compound, the complete organic cation, which adopts a typical chair conformation, is generated by crystallographic inversion symmetry and one of the N-bonded H atoms is half occupied. The sodium ion (site symmetry m) at the centre of the complex anion adopts a distorted trigonal–bipyramidal coordination geometry with the water mol­ecules in the equatorial sites and the bromide ions in the axial sites. In the extended structure, O—H⋯Br hydrogen bonds generate a porous ‘honeycomb' three-dimensional network of complex anions encapsulating [010] channels occupied by the cations.

In the bis-chelated mononuclear nickel(II) title complex with benzohydrazide ligands bearing an all­yloxy group, the nickel(II) atom exhibits a slightly distorted square-planar coordination environment with the metal located on a crystallographic center of symmetry that induces a trans configuration of the N,O chelating ligands..

The title compound is a derivative of cyclo­hexa­necarb­oxy­lic acid bearing a hydroxyl group in its α-position and is a polymorph of the previously reported monoclinic form.

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.

In the title compound, much of the mol­ecule (excluding the pyridinic ring) is approximately planar. In the extended structure, various hydrogen bonds combine to form a layer structure parallel to (111).

The title acridine derivative, which has two 2-methyl­but-3-yn-2-ol moieties at the 2,7-positions, was synthesized by Sonogashira coupling reaction. In crystal, a columnar structure is formed by the π–π stacking of acridine units. The 2-methyl­but-3-yn-2-ol moieties form inter­molecular hydrogen bonds.