The title salt, (PMIM)2[Ni(P2S8)2] (PMIM = 3-methyl-1-propyl-1H-imidazol-3-ium, C7H13N2+), consists of a nickel–thio­phosphate anion charge-balanced by a pair of crystallographically independent PMIM cations. It crystallizes in the monoclinic space group P21/n. The structure exhibits the known [Ni(P2S8)2]2− anion with two unique imidazolium cations in the asymmetric unit. Whereas one PMIM cation is well ordered, the other is disordered over two orientations with refined occupancies of 0.798 (2) and 0.202 (2). The salt was prepared directly from the elements in the ionic liquid [PMIM]CF3SO3. Whereas one of the PMIM cations is well behaved (it does not exhibit disorder even in the propyl side chain), the other is found in two overlapping positions. The refined occupancies for the two orientations are roughly 80:20. Here, too, there appears to be little disorder in the propyl arm.

Crystals of the dimethyl sulfoxide (DMSO) solvate of [1–9-NαC]-linusorb B3 (Cyclo­linopeptide A; CLP-A; C57H84N9O9·C2H6OS), a cyclic polypeptide were obtained following peptide extraction and purification from flaxseed oil. There are four intramolecular N—H⋯O hydrogen bonds. In the crystal, the mol­ecules are linked in chains along the a axis by N—H⋯O hydrogen bonds. Each DMSO O atom accepts a hydrogen bond from an NH group at the Phe6 location in the CLP-A mol­ecule.

A quinazolinthione, C17H14N2OS, was synthesized by the condensation reaction of 6,7,8,9-tetra­hydro-11H-pyrido[2,1-b]quinazolin-11-thione with furfural. The mol­ecule crystallizes in the monoclinic system (Cc space group) and has an E configuration with respect to the exocyclic C=C bond. In the crystal, mol­ecules are linked through C—H⋯π(furan) inter­actions, forming zigzag chains propagating along the [001] direction.

The mol­ecule of the title compound, C30H22N4, exhibits inversion symmetry adopting the shape of a St Andrew's Cross. It shows dihedral angles between adjacent aryl units of around 50° whereas torsion angles of ca 10° are found along the aryl­ene vinyl­ene path.

In the title compound, C14H11ClN2O2S, the dihedral angle between the pyrrolo­[1,2-c]pyrimidine ring system (r.m.s. deviation = 0.008 Å) and the benzene ring is 80.2 (9)°. In the crystal, inversion dimers linked by pairs of C—H⋯O inter­actions generate R22(16) loops. Several aromatic π–π stacking inter­actions between the pyrrolo­[1,2-c]pyrimidine rings, as well as separately between the pyrrolo and pyrimidine groups [shortest centroid–centroid separation = 3.5758 (14) Å], help to consolidate the packing.

In the title compound, C10H13N5, the piperidine ring adopts a chair conformation with the exocyclic N—C bond in an axial orientation, and the dihedral angle between the mean planes of piperidine and pyrimidine rings is 49.57 (11)°. A short intra­molecular C—H⋯N contact generates an S(7) ring. In the crystal, N—H⋯N hydrogen bonds link the mol­ecules into (100) sheets and a weak aromatic π-π stacking inter­action is observed [centroid–centroid separation = 3.5559 (11) Å] between inversion-related pyrimidine rings.

The reaction of ligand 5,7-di­hydro-1H,3H-dithieno[3,4-b:3',4'-e]pyrazine (L) with CuI lead to the formation of a three-dimensional coordination polymer, incorporating the well known [CuxIx]n staircase motif (x = 4). These polymer [Cu4I4]n chains are linked via the N and S atoms of the ligand to form the three-dimensional coordination polymer poly[(μ4-5,7-di­hydro-1H,3H-dithieno[3,4-b:3',4'-e]pyrazine-κ4N:N':S:S')tetra-μ3-iodido-tetra­copper], [Cu4I4(C8H8N2S2)]n (I). The asymmetric unit is composed of half a ligand mol­ecule, with the pyrazine ring located about a center of symmetry, and two independent copper(I) atoms and two independent I− ions forming the staircase motif via centers of inversion symmetry. The framework is consolidated by C—H⋯I hydrogen bonds.

The title hepta­nuclear alkoxido(oxido)vanadium(V) oxide cluster complex, [V7(C10H19O)O17(C18H24N2)3]·CH3CN, was obtained by the reaction of [V8O20(C18H24N2)4] with 4-tert-butyl­cyclo­hexa­nol (mixture of cis and trans) in a mixed CHCl3/CH3CN solvent. The complex has a V7O18N6 core with approximately Cs symmetry, which is composed of two VO4 tetra­hedra, two VO6 octa­hedra and three VO4N2 octa­hedra. In the crystal, these complexes are linked together by weak inter­molecular C—H⋯O hydrogen bonds between the 4,4'-di-tert-butyl-2,2'-bi­pyridine ligand and the V7O18N6 core, forming a one-dimensional network along the c-axis direction. Besides the complex, the asymmetric unit contains one CH3CN solvent mol­ecule. The contribution of other disordered solvent mol­ecules to the scattering was removed using the SQUEEZE option in PLATON [Spek (2015). Acta Cryst. C71, 9–18]. The unknown solvent mol­ecules are not considered in the chemical formula and other crystal data.

The reaction of ligand 3,4,8,10,11,13-hexa­hydro-1H,6H-bis­([1,4]di­thio­cino)[6,7-b:6',7'-e]pyrazine (L) with CuI led to the formation of a two-dimensional coordination polymer, incorporating a [Cu2I2] motif. These units are linked via the four S atoms of the ligand to form the title two-dimensional coordination poly­mer, poly[[μ4-3,4,8,10,11,13-hexa­hydro-1H,6H-bis­([1,4]di­thio­cino)[6,7-b:6',7'-e]pyrazine]di-μ-iodido-dicopper(I)], [Cu2I2(C12H16N2S4)]n, (I). The asymmetric unit is composed of a ligand mol­ecule, two copper(I) atoms and two I− ions. Both copper(I) atoms are fourfold S2I2 coordinate with almost regular trigonal-pyramidal environments. In the crystal, the layers, lying parallel to (102), are linked by C—H⋯I hydrogen bonds, forming a supra­molecular framework.

In the title compound, C20H21NO, the dihedral angle between the phenyl ring is 47.5 (1)° and the piperidine ring adopts a chair conformation. In the crystal, mol­ecules are linked by C—H⋯π inter­actions into dimers with the mol­ecules related by twofold symmetry.

The title compound, C52H40N2, is disposed about a centre of inversion and the conformation about the imine bond [1.268 (3) Å] is E. The terminal benzene ring is approximately perpendicular to the central 1,4-di­aza­butadiene mean plane, forming a dihedral angle of 81.2 (3)°. Weak C—H⋯π and π–π [inter-centroid distance = 4.021 (5) Å] inter­actions help to consolidate the packing.

The crystal structure of pirfenidone, C12H11NO [alternative name: 5-methyl-1-phenyl­pyridin-2(1H)-one], an active pharmaceutical ingredient (API) approved in Europe and Japan for the treatment of Idiopathic pulmonary fibrosis (IPF), is reported here for the first time. It was crystallized from toluene by the temperature gradient technique, and crystallizes in the chiral monoclinic space group P21. The phenyl and pyridone rings are inclined to each other by 50.30 (11)°. In the crystal, mol­ecules are linked by C–H⋯O hydrogen bonds involving the same acceptor atom, forming undulating layers lying parallel to the ab plane.

The title Schiff base compound, C13H9ClN4O5·0.5CH3CN, crystallizes as an aceto­nitrile hemisolvate; the solvent mol­ecule being located on a twofold rotation axis. The mol­ecule is nearly planar, with a dihedral angle between the two benzene rings of 3.7 (2)°. The configuration about the C=N bond is E, and there is an intra­molecular N—H⋯Onitro hydrogen bond present forming an S(6) ring motif. In the crystal, mol­ecules are linked by O—H⋯O and N—H⋯O hydrogen bonds, forming layers lying parallel to (10overline{1}). The layers are linked by C—H⋯Cl hydrogen bonds, forming a supra­molecular framework. Within the framework there are offset π–π stacking inter­actions [inter­centroid distance = 3.833 (2) Å] present involving inversion-related mol­ecules. The DFT study shows that the HOMO and LUMO are localized in the plane extending from the phenol ring to the 2,4-di­nitro­benzene ring, and the HOMO–LUMO gap is found to be 0.13061 a.u.

This work presents the synthesis and structural characterization of [4-(1H-benzo[d]imidazol-2-yl)phen­oxy]phthalo­nitrile, a phthalo­nitrile derivative carrying a benzimidazole moiety. The compound crystallizes as its dimethyl sulfoxide monosolvate, C21H12N4O·(CH3)2SO. The dihedral angle between the two fused rings in the heterocyclic ring system is 2.11 (1)°, while the phenyl ring attached to the imidazole moiety is inclined by 20.7 (1)° to the latter. In the crystal structure, adjacent mol­ecules are connected by pairs of weak inter­molecular C—H⋯N hydrogen bonds into inversion dimers. N—H⋯O and C—H⋯O hydrogen bonds with R21(7) graph-set motifs are also formed between the organic mol­ecule and the disordered dimethyl sulfoxide solvent [occupancy ratio of 0.623 (5):0.377 (5) for the two sites of the sulfur atom]. Hirshfeld surface analysis and fingerprint plots were used to investigate the inter­molecular inter­actions in the crystalline state.

The mol­ecule of the title Schiff base compound, C14H13N3O3·H2O, displays a trans configuration with respect to the C=N bond. The dihedral angle between the benzene and pyridine rings is 29.63 (7)°. The crystal structure features inter­molecular N—H⋯O, C—H⋯O, O—H⋯O and O—H⋯N hydrogen-bonding inter­actions, leading to the formation of a supramolecular framework. A Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from H⋯H (37.0%), O⋯H/H⋯O (23.7%)), C⋯H/H⋯C (17.6%) and N⋯H/H⋯N (11.9%) inter­actions. The title compound has also been characterized by frontier mol­ecular orbital analysis.

The title mol­ecule, C11H8F3NO3, adopts a cis configuration across the –C=C– double bond in the side chain and the dihedral angle between the phenyl ring and side chain is 47.35 (1)°. The –COOH group adopts a syn conformation (O=C—O—H = 0°), unlike the anti conformation observed in related maleamic acids. In the crystal, inversion dimers linked by pairs of O—H⋯O hydrogen bonds are connected via N—H⋯O hydrogen bonds and C—H⋯O inter­actions into (100) sheets, which are cross-linked by another C—H⋯O inter­action to result in a three-dimensional network. The Hirshfeld surface fingerprint plots show that the highest contribution to surface contacts arises from O⋯H/H⋯O contacts (26.5%) followed by H⋯F/F⋯H (23.4%) and H⋯H (17.3%).

The title compound, C15H15NO2, is a Schiff base that exists in the keto–enamine tautomeric form and adopts a Z configuration. The mol­ecule is almost planar, with the two phenyl rings twisted relative to each other by 9.60 (18)°. There is an intra­molecular N—H⋯O hydrogen bond present forming an S(6) ring motif. In the crystal, pairs of O—H⋯O hydrogen bonds link adjacent mol­ecules into inversion dimers with an R22(18) ring motif. The dimers are linked by very weak π–π inter­actions, forming layers parallel to (overline{2}01). Hirshfeld surface analysis, two-dimensional fingerprint plots and the mol­ecular electrostatic potential surfaces were used to analyse the inter­molecular inter­actions, indicating that the most important contributions for the crystal packing are from H⋯H (55.2%), C⋯H/H⋯C (22.3%) and O⋯H/H⋯O (13.6%) inter­actions.

The title compound, C14H12N2O4, is a Schiff base that exists in the keto–enamine tautomeric form and adopts a Z configuration. The mol­ecule is almost planar, the rings making a dihedral angle of 4.99 (7)°. The mol­ecular structure is stabilized by an intra­molecular N—H⋯O hydrogen bond forming an S(6) ring motif. In the crystal, inversion-related mol­ecules are linked by pairs of O—H⋯O hydrogen bonds, forming dimers with an R22(18) ring motif. The dimers are linked by pairs of C—H⋯O contacts with an R22(10) ring motif, forming ribbons extended along the [2overline{1}0] direction. Hirshfeld surface analysis, two-dimensional fingerprint plots and the mol­ecular electrostatic potential surfaces were used to analyse the inter­molecular inter­actions present in the crystal, indicating that the most important contributions for the crystal packing are from H⋯H (33.9%), O⋯H/H⋯O (29.8%) and C⋯H/H⋯C (17.3%) inter­actions.

The crystal structure of the title mol­ecular complex, [Ag2{VO2F2}2(C13H17N3O2)4]·4H2O, supported by the heterofunctional ligand tr-ad-COOH [1-(1,2,4-triazol-4-yl)-3-carb­oxy­adamantane] is reported. Four 1,2,4-triazole groups of the ligand link two AgI atoms, as well as AgI and VV centres, forming the heterobimetallic coordination cluster {AgI2(VVO2F2)2(tr)4}. VV exists as a vanadium oxofluoride anion and possesses a distorted trigonal–bipyramidal coordination environment [VO2F2N]. A carb­oxy­lic acid functional group of the ligand stays in a neutral form and is involved in hydrogen bonding with solvent water mol­ecules and VO2F2− ions of adjacent mol­ecules. The extended hydrogen-bonding network is responsible for the crystal packing in the structure.

In the title compound, [Cd2(C6H9N3O2)2Cl6], the coordination polyhedra around the CdII cations are distorted trigonal bipyramids. Two of the chloride ions (one axial and one equatorial) are bridging to the other metal atom, leading to a Cd⋯Cd separation of 3.9162 (4) Å. The O atom of the l-histidinium cation lies in an axial site. In the crystal, numerous N—H⋯Cl, N—H⋯O, C—H⋯O and C—H⋯Cl hydrogen bonds link the mol­ecules into a three-dimensional network. Theoretical calculations and spectroscopic data are available as supporting information.

A new polymorph of the title compound, C10H13NO, was obtained by recrystallization of the commercial product from a water/ethanol mixture (1:1 v/v). Crystals of the previously reported racemic and homochiral forms of 2-phenyl­butyramide were grown from water–aceto­nitrile solution in 1:1 volume ratio [Khrustalev et al. (2014). Cryst. Growth Des. 14, 3360–3369]. While the previously reported racemic and enanti­opure forms of the title compound adopt very similar supra­molecular structures (hydrogen-bonded ribbons), the new racemic polymorph is stabilized by a single N—H⋯O hydrogen bond that links mol­ecules into chains along the c-axis direction with an anti­parallel (centrosymmetric) packing in the crystal. Hirshfeld mol­ecular surface analysis was employed to compare the inter­molecular inter­actions in the polymorphs of the title compound.

The title compound, C9H11NO2, was obtained as unexpected product from the reaction of (4-{2-benz­yloxy-5-[(E)-(3-chloro-4-methyl­phen­yl)diazen­yl]benzyl­idene}-2-phenyl­oxazol-5(4H)-one) with 2-meth­oxy­aniline in the presence of acetic acid as solvent. The amide group is not coplanar with the benzene ring, as shown by the C—N—C—O and C—N—C—C torsion angles of −2.5 (3) and 176.54 (19)°, respectively. Hirshfeld surface analysis and two-dimensional fingerprint plots indicate that the most important contributions to the crystal packing are from H⋯H (53.9%), C⋯H/H⋯C (21.4%), O⋯H/H⋯O (21.4%) and N⋯H/H⋯N (1.7%) inter­actions.

The title compound, [Ni(C10H8N2)3](C9H5N4O)2·2H2O, crystallizes as a racemic mixture in the monoclinic space group C2/c. In the crystal, the 1,1,3,3-tetracyano-2-ethoxypropenide anions and the water molecules are linked by O—H⋯N hydrogen bonds, forming chains running along the [010] direction. The bpy ligands of the cation are linked to the chain via C—H⋯π(cation) inter­actions involving the CH3 group. The inter­molecular inter­actions were investigated by Hirshfeld surface analysis and two-dimensional fingerprint plots.

The title compound, C13H24O9·H2O, a structural model for part of bacterial O-anti­gen polysaccharides from Shigella flexneri and Escherichia coli, crystallizes with four independent disaccharide mol­ecules and four water mol­ecules in the asymmetric unit. The conformation at the glycosidic linkage joining the two rhamnosyl residues is described by the torsion angles φH of 39, 30, 37 and 37°, and ψH of −32, −35, −31 and −32°, which are the major conformation region known to be populated in an aqueous solution. The hexo­pyran­ose rings have the 1C4 chair conformation. In the crystal, the disaccharide and water mol­ecules are associated through O—H⋯O hydrogen bonds, forming a layer parallel to the bc plane. The layers stack along the a axis via hydro­phobic inter­actions between the methyl groups.

The solvated centrosymmmtric title compound, [Li2(C24H34O4P)2(C10H8N2)2]·2C7H8, was formed in the reaction between {Li[(2,6-iPr2C6H3-O)2POO](MeOH)3}(MeOH) and 2,2'-bi­pyridine (bipy) in toluene. The structure has monoclinic (P21/n) symmetry at 120 K and the asymmetric unit consists of half a complex mol­ecule and one mol­ecule of toluene solvent. The diaryl phosphate ligand demonstrates a μ-κO:κO'-bridging coordination mode and the 2,2'-bi­pyridine ligand is chelating to the Li+ cation, generating a distorted tetra­hedral LiN2O2 coordination polyhedron. The complex exhibits a unique dimeric Li2O4P2 core. One isopropyl group is disordered over two orientations in a 0.621 (4):0.379 (4) ratio. In the crystal, weak C—H⋯O and C—H⋯π inter­actions help to consolidate the packing. Catalytic systems based on the title complex and on the closely related complex {Li[(2,6-iPr2C6H3-O)2POO](MeOH)3}(MeOH) display activity in the ring-opening polymerization of ∊-caprolactone and l-dilactide.

The structure of zymonic acid (systematic name: 4-hy­droxy-2-methyl-5-oxo-2,5-di­hydro­furan-2-carb­oxy­lic acid), C6H6O5, which had previously eluded crystallographic determination, is presented here for the first time. It forms by intra­molecular condensation of parapyruvic acid, which is the product of aldol condensation of pyruvic acid. A redetermination of the crystal structure of pyruvic acid (systematic name: 2-oxo­propanoic acid), C3H4O3, at low temperature (90 K) and with increased precision, is also presented [for the previous structure, see: Harata et al. (1977). Acta Cryst. B33, 210–212]. In zymonic acid, the hy­droxy­lactone ring is close to planar (r.m.s. deviation = 0.0108 Å) and the dihedral angle between the ring and the plane formed by the bonds of the methyl and carb­oxy­lic acid carbon atoms to the ring is 88.68 (7)°. The torsion angle of the carb­oxy­lic acid group relative to the ring is 12.04 (16)°. The pyruvic acid mol­ecule is almost planar, having a dihedral angle between the carb­oxy­lic acid and methyl-ketone groups of 3.95 (6)°. Inter­molecular inter­actions in both crystal structures are dominated by hydrogen bonding. The common R22(8) hydrogen-bonding motif links carb­oxy­lic acid groups on adjacent mol­ecules in both structures. In zymonic acid, this results in dimers about a crystallographic twofold of space group C2/c, which forces the carb­oxy­lic acid group to be disordered exactly 50:50, which scrambles the carbonyl and hydroxyl groups and gives an apparent equalization of the C—O bond lengths [1.2568 (16) and 1.2602 (16) Å]. The other hydrogen bonds in zymonic acid (O—H⋯O and weak C—H⋯O), link mol­ecules across a 21-screw axis, and generate an R22(9) motif. These hydrogen-bonding inter­actions propagate to form extended pleated sheets in the ab plane. Stacking of these zigzag sheets along c involves only van der Waals contacts. In pyruvic acid, inversion-related mol­ecules are linked into R22(8) dimers, with van der Waals inter­actions between dimers as the only other inter­molecular contacts.

The title binuclear CoIII complex, [Co2(C9H8BrNOS)2(C18H16Br2N2O2S2)]·C3H7NO, with a Schiff base ligand formed in situ from cyste­amine (2-amino­ethane­thiol) and 5-bromo­salicyl­aldehyde crystallizes in the space group P21. It was found that during the synthesis the ligand undergoes spontaneous oxidation, forming the new ligand H2L' having an S—S bond. Thus, the asymmetric unit consists of one Co2(L)2(L') mol­ecule and one DMF solvent mol­ecule. Each CoIII ion has a slightly distorted octa­hedral S2N2O2 coordination geometry. In the crystal, the components are linked into a three-dimensional network by several S⋯ Br, C⋯ Br, C—H⋯Br, short S⋯C (essentially shorter than the sum of the van der Waals radii for the atoms involved) contacts as well by weak C—H⋯O hydrogen bonds. The crystal studied was refined as an inversion twin.

The title pyridazinone derivative, C21H19ClN2O3, is not planar. The unsubstituted phenyl ring and the pyridazine ring are inclined to each other, making a dihedral angle of 17.41 (13)° whereas the Cl-substituted phenyl ring is nearly orthogonal to the pyridazine ring [88.19 (13)°]. In the crystal, C—H⋯O hydrogen bonds generate dimers with R22(10) and R22(24) ring motifs which are linked by C—H⋯O inter­actions, forming chains extending parallel to the c-axis direction. The inter­molecular inter­actions were investigated using Hirshfeld surface analysis and two-dimensional fingerprint plots, revealing that the most significant contributions to the crystal packing are from H⋯H (44.5%), C⋯H/H⋯C (18.5%), H⋯O/H⋯O (15.6%), Cl⋯H/H⋯Cl (10.6%) and C⋯C (2.8%) contacts.

Six reaction products of ZnII and NiII with pyridine-2,6-di­carb­oxy­lic acid (H2Lig1), 4-chloro­pyridine-2,6-di­carb­oxy­lic acid (H2Lig2) and 4-hy­droxy­pyridine-2,6-di­carb­oxy­lic acid (H2Lig3) are used to pinpoint the structural consequences of crystal field stabilization by an incomplete d shell. The pseudo-octa­hedral ZnII coordination sphere in bis­(6-carb­oxy­picolinato)zinc(II) trihydrate, [Zn(C7H4NO4)2]·3H2O or [Zn(HLig1)2]·3H2O, (1), is significantly less regular than that about NiII in the isostructural compound bis­(6-carb­oxy­picolinato)nickel(II) trihydrate, [Ni(C7H4NO4)2]·3H2O or [Ni(HLig1)2]·3H2O, (2). The ZnII complexes poly[(4-chloro­pyridine-2,6-di­carboxyl­ato)zinc(II)], [Zn(C7H2ClNO4)]n or [Zn(Lig2)]n, (3), and poly[[(4-hy­droxy­pyridine-2,6-di­carboxyl­ato)zinc(II)] monohydrate], {[Zn(C7H3NO5)]·H2O}n or {[Zn(Lig3)]·H2O}n, (4), represent two-dimensional coordination polymers with chelating and bridging pyridine-2,6-di­carboxyl­ate ligands in which the coordination polyhedra about the central cations cannot be associated with any regular shape; their coordination environments range between trigonal–bipyramidal and square-pyramidal geometries. In contrast, the corresponding adducts of the diprotonated ligands to NiII, namely tri­aqua­(4-chloro­pyridine-2,6-di­carboxyl­ato)nickel(II), [Ni(C7H2ClNO4)(H2O)3] or [NiLig2(OH2)3)], (5), and tri­aqua­(4-hy­droxy­pyridine-2,6-di­carboxyl­ato)nickel(II) 1.7-hydrate, [Ni(C7H3NO5)(H2O)3]·1.7H2O or [NiLig3(OH2)3)]·1.7H2O, (6), feature rather regular octa­hedral coordination spheres about the transition-metal cations, thus precluding the formation of analogous extended structures.

The title compound, [Fe2(C44H28N4O)2O], was obtained as a by-product during the synthesis of FeIII tetra­phenyl­porphyrin perchlorate. It crystallizes as a new polymorphic modification in addition to the ortho­rhom­bic form previously reported [Hoffman et al. (1972). J. Am. Chem. Soc. 94, 3620–3626; Swepston & Ibers (1985) Acta Cryst. C41, 671–673; Kooijmann et al. (2007). Private Communication (refcode 667666). CCDC, Cambridge, England]. In its crystal structure, the two crystallographically independent FeIII cations are coordinated in a square-planar environment by the four N atoms of a tetra­phenyl­porphyrin ligand. The FeIII-tetra­phenyl­porphyrine units are linked by a μ2-oxido ligand into a dimer with an Fe—O—Fe angle close to linearity. The final coordination sphere for each FeIII atom is square-pyramidal with the μ2-oxido ligand in the apical position. The crystal under investigation consisted of two domains in a ratio of 0.691 (3): 0.309 (3).

In the title compound, C20H18NO3P, the C=O and P=O groups of the carbacyl­amido­phosphate (CAPh) fragments are located in a synclinal position relative to each other and are pre-organized for bidentate chelate coordination of metal ions. The N—H group is involved in the formation of an intra­molecular hydrogen bond. In the crystal, mol­ecules do not form strong inter­molecular inter­actions but the mol­ecules are linked via weak C—H⋯π inter­actions, forming chains along [001].

A new quinoline-based hydrazone, C16H12ClN3, was synthesized by a condensation reaction of 2-chloro-3-formyl­quinoline with phenyl­hydrazine. The quinoline ring system is essentially planar (r.m.s. deviation = 0.012 Å), and forms a dihedral angle of 8.46 (10)° with the phenyl ring. The mol­ecule adopts an E configuration with respect to the central C=N bond. In the crystal, mol­ecules are linked by a C—H⋯π-phenyl inter­action, forming zigzag chains propagating along the [10overline{3}] direction. The N—H hydrogen atom does not participate in hydrogen bonding but is directed towards the phenyl ring of an adjacent mol­ecule, so linking the chains via weak N—H⋯π inter­actions to form of a three-dimensional structure. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions to the crystal packing are from H⋯H (35.5%), C⋯H/H⋯C (33.7%), Cl⋯H/H⋯Cl (12.3%), N⋯H/H⋯N (9.5%) contacts.

The asymmetric unit of the title compound, [Fe(NCS)2(C12H9NO)4], consists of an FeII ion that is located on a centre of inversion, as well as two 4-benzoyl­pyridine ligands and one thio­cyanate anion in general positions. The FeII ions are coordinated by two N-terminal-bonded thio­cyanate anions and four 4-benzoyl­pyridine ligands into discrete complexes with a slightly distorted octa­hedral geometry. These complexes are further linked by weak C—H⋯O hydrogen bonds into chains running along the c-axis direction. Upon heating, this complex loses half of the 4-benzoyl­pyridine ligands and transforms into a compound with the composition Fe(NCS)2(4-benzoyl­pyridine)2, that might be isotypic to the corresponding MnII compound and for which the structure is unknown.

The title compound, C22H22N2O4S2, was synthesized by the reaction of 1,4,5,8-naphthalene­tetra­carb­oxy­lic dianhydride with 3-(methyl­sulfan­yl)propyl­amine. The whole mol­ecule is generated by an inversion operation of the asymmetric unit. This mol­ecule has an anti form with the terminal methyl­thio­propyl groups above and below the aromatic di­imide plane, where four intra­molecular C—H⋯O and C—H⋯S hydrogen bonds are present and the O⋯H⋯S angle is 100.8°. DFT calculations revealed slight differences between the solid state and gas phase structures. In the crystal, C—H⋯O and C—H⋯S hydrogen bonds link the mol­ecules into chains along the [2overline20] direction. adjacent chains are inter­connected by π–π inter­actions, forming a two-dimensional network parallel to the (001) plane. Each two-dimensional layer is further packed in an ABAB sequence along the c-axis direction. Hirshfeld surface analysis shows that van der Waals inter­actions make important contributions to the inter­molecular contacts. The most important contacts found in the Hirshfeld surface analysis are H⋯H (44.2%), H⋯O/O⋯H (18.2%), H⋯C/C⋯H (14.4%), and H⋯S/S⋯H (10.2%).

The title compound, C21H16N2O2, consists of an imidazolidine unit linked to two phenyl rings and two prop-2-yn-1-yl moieties. The imidazolidine ring is oriented at dihedral angles of 79.10 (5) and 82.61 (5)° with respect to the phenyl rings, while the dihedral angle between the two phenyl rings is 62.06 (5)°. In the crystal, inter­molecular C—HProp⋯OImdzln (Prop = prop-2-yn-1-yl and Imdzln = imidazolidine) hydrogen bonds link the mol­ecules into infinite chains along the b-axis direction. Two weak C—HPhen⋯π inter­actions are also observed. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (43.3%), H⋯C/C⋯H (37.8%) and H⋯O/O⋯H (18.0%) inter­actions. Hydrogen bonding and van der Waals inter­actions are the dominant inter­actions in the crystal packing. Computational chemistry indicates that the C—HProp⋯OImdzln hydrogen-bond energy in the crystal is −40.7 kJ mol−1. Density functional theory (DFT) optimized structures at the B3LYP/6–311G(d,p) level are compared with the experimentally determined mol­ecular structure in the solid state. The HOMO–LUMO behaviour was elucidated to determine the energy gap.

Typical electroless copper baths (ECBs), which are used to chemically deposit copper on printed circuit boards, consist of an aqueous alkali hydroxide solution, a copper(II) salt, formaldehyde as reducing agent, an l-(+)-tartrate as complexing agent, and a 2,2'-bi­pyridine derivative as stabilizer. Actual speciation and reactivity are, however, largely unknown. Herein, we report on the synthesis and crystal structure of aqua-1κO-bis­(4,4'-dimeth­oxy-2,2'-bi­pyri­dine)-1κ2N,N';2κ2N,N'-[μ-(2R,3R)-2,3-dioxidosuccinato-1κ2O1,O2:2κ2O3,O4]dicopper(II) octa­hydrate, [Cu2(C12H12N2O2)2(C4H2O6)(H2O)]·8H2O, from an ECB mock-up. The title compound crystallizes in the Sohncke group P21 with one chiral dinuclear complex and eight mol­ecules of hydrate water in the asymmetric unit. The expected retention of the tartrato ligand's absolute configuration was confirmed via determination of the absolute structure. The complex mol­ecules exhibit an ansa-like structure with two planar, nearly parallel bi­pyridine ligands, each bound to a copper atom that is connected to the other by a bridging tartrato `handle'. The complex and water mol­ecules give rise to a layered supra­molecular structure dominated by alternating π stacks and hydrogen bonds. The understanding of structures ex situ is a first step on the way to prolonged stability and improved coating behavior of ECBs.

The coordination of the ligands with respect to the central atom in the complex bromido­tricarbon­yl[diphen­yl(pyridin-2-yl)phosphane-κ2N,P]rhenium(I) chloro­form disolvate, [ReBr(C17H14NP)(CO)3]·2CHCl3 or [κ2-P,N-{(C6H5)2(C5H5N)P}Re(CO)3Br]·2CHCl3, (I·2CHCl3), is best described as a distorted octa­hedron with three carbonyls in a facial conformation, a bromide atom, and a biting P,N-di­phenyl­pyridyl­phosphine ligand. Hirshfeld surface analysis shows that C—Cl⋯H inter­actions contribute 26%, the distance of these inter­actions are between 2.895 and 3.213 Å. The reaction between I and piperidine (C5H11N) at 313 K in di­chloro­methane leads to the partial decoord­ination of the pyridyl­phosphine ligand, whose pyridyl group is replaced by a piperidine mol­ecule, and the complex bromido­tricarbon­yl[diphen­yl(pyridin-2-yl)phosphane-κP](piperidine-κN)rhenium(I), [ReBr(C5H11N)(C17H14NP)(CO)3] or [P-{(C6H5)2(C5H5N)P}(C5H11N)Re(CO)3Br] (II). The mol­ecule has an intra­molecular N—H⋯N hydrogen bond between the non-coordinated pyridyl nitro­gen atom and the amine hydrogen atom from piperidine with D⋯A = 2.992 (9) Å. Thermogravimetry shows that I·2CHCl3 losses 28% of its mass in a narrow range between 318 and 333 K, which is completely consistent with two solvating chloro­form mol­ecules very weakly bonded to I. The remaining I is stable at least to 573 K. In contrast, II seems to lose solvent and piperidine (12% of mass) between 427 and 463 K, while the additional 33% loss from this last temperature to 573 K corresponds to the release of 2-pyridyl­phosphine. The contribution to the scattering from highly disordered solvent mol­ecules in II was removed with the SQUEEZE routine [Spek (2015). Acta Cryst. C71, 9-18] in PLATON. The stated crystal data for Mr, μ etc. do not take this solvent into account.

The asymmetric unit of the title compound, C15H12N2O2, contains two crystallographically independent mol­ecules in which the dihedral angles between the benzene rings in each are 13.26 (5) and 7.87 (5)°. An intra­molecular O—H⋯N hydrogen bonds results in the formation of an S(6) ring motif. In the crystal, mol­ecules are linked by weak C—H⋯O and C—H⋯N hydrogen bonds, forming layers parallel to (011). In addition, π–π stacking inter­actions with centroid–centroid distances in the range 3.693 (2)–3.931 (2) Å complete the three-dimensional network.

Two bis-carbamoyl­methyl­phosphine oxide compounds, namely {[(3-{[2-(di­phen­yl­phosphino­yl)ethanamido]­meth­yl}benz­yl)carbamo­yl]meth­yl}di­phenyl­phos­phine oxide, C36H34N2O4P2, (I), and diethyl [({2-[2-(di­eth­oxy­phosphino­yl)ethanamido]­eth­yl}carbamo­yl)meth­yl]phospho­nate, C14H30N2O8P2, (II), were synthesized via nucleophilic acyl substitution reactions between an ester and a primary amine. Hydrogen-bonding inter­actions are present in both crystals, but these inter­actions are intra­molecular in the case of compound (I) and inter­molecular in compound (II). Intra­molecular π–π stacking inter­actions are also present in the crystal of compound (I) with a centroid–centroid distance of 3.9479 (12) Å and a dihedral angle of 9.56 (12)°. Inter­molecular C—H⋯π inter­actions [C⋯centroid distance of 3.622 (2) Å, C—H⋯centroid angle of 146°] give rise to supra­molecular sheets that lie in the ab plane. Key geometric features for compound (I) involve a nearly planar, trans-amide group with a C—N—C—C torsion angle of 169.12 (17)°, and a torsion angle of −108.39 (15)° between the phosphine oxide phospho­rus atom and the amide nitro­gen atom. For compound (II), the electron density corresponding to the phosphoryl group was disordered, and was modeled as two parts with a 0.7387 (19):0.2613 (19) occupancy ratio. Compound (II) also boasts a trans-amide group that approaches planarity with a C—N—C—C torsion angle of −176.50 (16)°. The hydrogen bonds in this structure are inter­molecular, with a D⋯A distance of 2.883 (2) Å and a D—H⋯A angle of 175.0 (18)° between the amide hydrogen atom and the P=O oxygen atom. These non-covalent inter­actions create ribbons that run along the b-axis direction.

The structures of two isomers of the title compound, [RuCl2(C14H12N4)(C2H6OS)2], 2 and 3, are reported. Isomers 2 and 3 are produced by reaction of the pyridyl­triazole ligand 1-benzyl-4-(pyridin-2-yl)-1H-1,2,3-triazole (bpt) (1) with fac-[RuCl2(DMSO-S)3(DMSO-O)]. Reaction in acetone produces ca 95% 2, which is the OC-6-14 isomer, with cis DMSO and trans chlorido ligands, and 5% 3 (the OC-6-32 isomer, with cis DMSO and cis chlorido ligands, and the pyridyl moiety of bpt trans to DMSO). Reaction in refluxing toluene initially forms 2, which slowly isomerizes to 3.

The asymmetric units of the title compounds, trans-di­aqua­(3-benzyl-1,3,5,8,12-penta­aza­cyclo­tetra­decane-κ4N1,N5,N8,N12)copper(II) isophthalate monohydrate, [Cu(C16H29N5)(H2O)2](C8H4O4)·H2O, (I), and trans-di­aqua­[3-(pyridin-3-ylmeth­yl)-1,3,5,8,12-penta­aza­cyclo­tetra­decane-κ4N1,N5,N8,N12]copper(II) iso­phthalate 0.9-hydrate, [Cu(C15H28N6)(H2O)2](C8H4O4)·0.9H2O, (II) consist of one di­aqua macrocyclic cation, one di­carboxyl­ate anion and uncoordinated water mol­ecule(s). In each compound, the metal ion is coordinated by the four secondary N atoms of the macrocyclic ligand and the mutually trans O atoms of the water mol­ecules in a tetra­gonally distorted octa­hedral geometry. The average equatorial Cu—N bond lengths are significantly shorter than the average axial Cu—O bond lengths [2.020 (9) versus 2.495 (12) Å and 2.015 (4) versus 2.507 (7) Å for (I) and (II), respectively]. The coordinated macrocyclic ligand in the cations of both compounds adopts the most energetically favorable trans-III conformation. In the crystals, the complex cations and counter-anions are connected via hydrogen-bonding inter­actions between the N—H groups of the macrocycles and the O—H groups of coordinated water mol­ecules as the proton donors and the O atoms of the carboxyl­ate as the proton acceptors. Additionally, as a result of O—H⋯O hydrogen bonding with the coordinated and water mol­ecules of crystallization, the isophthalate dianions form layers lying parallel to the (overline{1}01) and (100) planes in (I) and (II), respectively.

The title compound, hexa­kis­(2-methyl-1H-imidazol-3-ium) hepta­molybdate 2-methyl-1H-imidazole disolvate dihydrate, (C4H7N2)6[Mo7O24]·2C4H6N2·2H2O, was prepared from 2-methyl­imidazole and ammonium hepta­molybdate tetra­hydrate in acid solution. The [Mo7O24]6− hepta­molybdate cluster anion is accompanied by six protonated (C4H7N2)+ 2-methyl­imidazolium cations, two neutral C4H6N2 2-methyl­imidazole mol­ecules and two water mol­ecules of crystallization. The cluster consists of seven distorted MoO6 octa­hedra sharing edges or vertices. In the crystal, the components are linked by N—H⋯N, N—H⋯O, O—H⋯O, N—H⋯(O,O) and O—H⋯(O,O) hydrogen bonds, generating a three-dimensional network. Weak C—H⋯O inter­actions consolidate the packing.

The title pyridazin-3(2H)-one derivative, C25H19FN2O2, crystallizes with two independent mol­ecules (A and B) in the asymmetric unit. In mol­ecule A, the 4-fluoro­phenyl ring, the benzyl ring and the phenyl ring are inclined to the central pyridazine ring by 86.54 (11), 3.70 (9) and 84.857 (13)°, respectively. In mol­ecule B, the corresponding dihedral angles are 86.80 (9), 10.47 (8) and 82.01 (10)°, respectively. In the crystal, the A mol­ecules are linked by pairs of C—H⋯F hydrogen bonds, forming inversion dimers with an R22(28) ring motif. The dimers are linked by C—H⋯O hydrogen bonds and a C—H⋯π inter­action, forming columns stacking along the a-axis direction. The B mol­ecules are linked to each other in a similar manner and form columns separating the columns of A mol­ecules.

The title compounds, C14H10ClFN2OS (1) and C14H10BrFN2OS (2), were synthesized by two-step reactions. The dihedral angles between the aromatic rings are 31.99 (3) and 9.17 (5)° for 1 and 2, respectively. Compound 1 features an intra­molecular bifurcated N—H⋯(O,Cl) link due to the presence of the ortho-Cl atom on the benzene ring, whereas 2 features an intra­molecular N—H⋯O hydrogen bond. In the crystal of 1, inversion dimers linked by pairs of N—H⋯S hydrogen bonds generate R22(8) loops. The extended structure of 2 features the same motif but an additional weak C—H⋯S inter­action links the inversion dimers into [100] double columns. Hirshfeld surface analyses indicate that the most important contributors towards the crystal packing are H⋯H (26.6%), S⋯H/H.·S (13.8%) and Cl⋯H/H⋯Cl (9.5%) contacts for 1 and H⋯H (19.7%), C⋯H/H⋯C (14.8%) and Br⋯H/H⋯Br (12.4%) contacts for 2.

The title tetra­nuclear copper complex, [Cu4Cl6O(C6H9N3O3)4] or [Cu4Cl6O­(MET)4] [MET is 1-(2-hy­droxy­eth­yl)-2-methyl-5-nitro-1H-imidazole or metronidazole], contains a tetra­hedral arrangement of copper(II) ions. Each copper atom is also linked to the other three copper atoms in the tetra­hedron via bridging chloride ions. A fifth coordination position on each metal atom is occupied by a nitro­gen atom of the monodentate MET ligand. The result is a distorted CuCl3NO trigonal–bipyramidal coordination polyhedron with the axial positions occupied by oxygen and nitro­gen atoms. The extended structure displays O—H⋯O hydrogen bonding, as well as unusual short O⋯N inter­actions [2.775 (4) Å] between the nitro groups of adjacent clusters that are oriented perpendicular to each other. The scattering contribution of disordered water and methanol solvent mol­ecules was removed using the SQUEEZE procedure [Spek (2015). Acta Cryst. C71, 9–16] in PLATON [Spek (2009). Acta Cryst. D65, 148–155].

The reaction of 2,5-bis­(pyridin-4-yl)-1,3,4-oxa­diazole (4-pox) and thio­cyanate ions, used as co-ligand with nickel salt NiCl2·6H2O, produced the title complex, [Ni(NCS)2(C12H8N4O)2(H2O)2]. The NiII atom is located on an inversion centre and is octa­hedrally coordinated by four N atoms from two ligands and two pseudohalide ions, forming the equatorial plane. The axial positions are occupied by two O atoms of coordinated water mol­ecules. In the crystal, the mol­ecules are linked into a three-dimensional network through strong O—H⋯N hydrogen bonds. Hirshfeld surface analysis was used to investigate the inter­molecular inter­actions in the crystal packing.

The title mol­ecule crystallizes as a di­methyl­formamide monosolvate, C19H14N2O6S2·C3H7NO. The mol­ecule was expected to adopt mirror symmetry but slightly different conformational characteristics of the condensed benzo­thia­zine ring lead to point group symmetry 1. In the crystal, mol­ecules form two types of stacking dimers with distances of 3.464 (2) Å and 3.528 (2) Å between π-systems. As a result, columns extending parallel to [100] are formed, which are connected to inter­mediate di­methyl­formamide solvent mol­ecules by C—H⋯O inter­actions.

The synthesis, spectroscopic data, crystal and mol­ecular structures of two N'-(1-phenyl­benzyl­idene)-2-(thio­phen-3-yl)acetohydrazides, namely N'-[1-(4-hy­droxy­phen­yl)benzyl­idene]-2-(thio­phen-3-yl)acetohydrazide, C13H10N2O2S, (3a), and N'-[1-(4-meth­oxy­phen­yl)benzyl­idene]-2-(thio­phen-3-yl)acetohydrazide, C14H14N2O2S, (3b), are described. Both compounds differ in the substituent at the para position of the phenyl ring: –OH for (3a) and –OCH3 for (3b). In (3a), the thio­phene ring is disordered over two orientations with occupancies of 0.762 (3) and 0.238 (3). The configuration about the C=N bond is E. The thio­phene and phenyl rings are inclined by 84.0 (3) and 87.0 (9)° for the major- and minor-occupancy disorder components in (3a), and by 85.89 (12)° in (3b). Although these dihedral angles are similar, the conformation of the linker between the two rings is different [the C—C—C—N torsion angle is −ac for (3a) and −sc for (3b), while the C6—C7—N9—N10 torsion angle is +ap for (3a) and −sp for (3b)]. A common feature in the crystal packing of (3a) and (3b) is the presence of N—H⋯O hydrogen bonds, resulting in the formation of chains of mol­ecules running along the b-axis direction in the case of (3a), or inversion dimers for (3b). The most prominent contributions to the surface contacts are those in which H atoms are involved, as confirmed by an analysis of the Hirshfeld surface.

Two CuII complexes [Cu(C14H13N4O2)Cl]n, I, and [Cu4(C8H10NO2)4Cl4]n, II, have been synthesized. In the structure of the mononuclear complex I, each ligand is coordinated to two metal centers. The basal plane around the CuII cation is formed by one chloride anion, one oxygen atom, one imino and one pyridine nitro­gen atom. The apical position of the distorted square-pyramidal geometry is occupied by a pyridine nitro­gen atom from a neighbouring unit, leading to infinite one-dimensional polymeric chains along the b-axis direction. Each chain is connected to adjacent chains by inter­molecular C—H⋯O and C—H⋯Cl inter­actions, leading to a three-dimensional network structure. The tetra­nuclear complex II lies about a crystallographic inversion centre and has one core in which two CuII metal centers are mutually inter­connected via two enolato oxygen atoms while the other two CuII cations are linked by a chloride anion and an enolato oxygen. An open-cube structure is generated in which the two open-cube units, with seven vertices each, share a side composed of two CuII ions bridged by two enolato oxygen atoms acting in a μ3-mode. The CuII atoms in each of the two CuO3NCl units are connected by one μ2-O and two μ3-O atoms from deprotonated hydroxyl groups and one chloride anion to the three other CuII centres. Each of the penta­coordinated CuII cations has a distorted NO3Cl square-pyramidal environment. The CuII atoms in each of the two CuO2NCl2 units are connected by μ2-O and μ3-O atoms from deprotonated alcohol hy­droxy groups and one chloride anion to two other CuII ions. Each of the penta­coordinated CuII cations has a distorted NO2Cl2 square-pyramidal environment. In the crystal, a series of intra­molecular C—H⋯O and C—H⋯Cl hydrogen bonds are observed in each tetra­nuclear monomeric unit, which is connected to four tetra­nuclear monomeric units by inter­molecular C—H⋯O hydrogen bonds, thus forming a planar two-dimensional structure in the (overline{1}01) plane.

In each of the two independent mol­ecules in the asymmetric unit of the title compound, [CdI2(C18H14N4O)], the N,O,N'-tridentate N'-[(E)-(phen­yl)(pyridin-2-yl-κN)methyl­idene]pyridine-2-carbohydrazide ligand and two iodide anions form an I2N2O penta­coordination sphere, with a distorted square-pyramidal geometry, with an I atom in the apical position. Both mol­ecules feature an intra­molecular N—H⋯N hydrogen bond. In the crystal, weak aromatic π–π stacking inter­actions [centroid–centroid separation = 3.830 (2) Å] link the mol­ecules into dimers.