In the title compound, [Cd4Cl8(C6H16N2)4], the Cd2+ cations and Cl− anions form M4Cl8 clusters with six of the Cl− ions bridging Cd2+ cations and two being pendant. Each Cd2+ cation has distorted octa­hedral coordination completed by four Cl− ions and two N atoms of the asymmetrical bidentate amino ligand. The cluster consists of pairs of face-sharing hexa­hedra linked by a shared edge.

The title compound, {(C9H11N2)[Mn(NCS)3]}n, has been obtained as a side product of the salt metathesis reaction of 1-ethyl-3-methyl­imidazolium bromide, (EMIm)Br, and K2[Mn(NCS)4]. The structure consists of discrete 1-ethyl-3-methyl­imidazolium cations and an anionic two-dimensional network of manganese(II)-based complex anions, inter­connected by thio­cyanate ions. Every Mn2+ ion is coordinated by three S atoms of three NCS− ions and three N atoms of further three NCS− ions in a meridional octa­hedral fashion.

In the title compound, C31H24Br2Cl2N2O, the dihedral angles subtended by the tert-butyl-phenyl, 4,6-di­chloro­phenol and 4-bromo­phenyl (×2) rings are 70.7 (3), 8.1 (3), 28.1 (3) and 84.2 (3)°, respectively. The orientations of the pendant rings may be related to intra­molecular O—H⋯N and C—H⋯π inter­actions. One of the tert-butyl methyl groups is disordered over two sets of sites in a 0.54 (3):0.46 (3) ratio. In the crystal, a weak C—H⋯π inter­action generates inversion dimers.

In the title hydrated salt, [Ni(C21H17F2N3)2](NO3)2·2H2O, the central NiII ion is coordinated by six N atoms from two tridentate chelating 2,6-bis­[(E)-(4-fluoro­benzyl­imino)­meth­yl]pyridine ligands. While the central NiII ion is six-coordinate, its environment is distorted from an octa­hedral structure because of the unequal Ni—N distances. The Ni—N bond lengths vary from 1.8642 (14) to 2.2131 (15) Å, while the N—Ni—N angles range from 79.98 (6) to 104.44 (6)°. Three coordinating sites of each chelating agent are almost coplanar with respect to the pyridine ring, and two pyridine moieties are perpendicular to each other. Two non-coordinating nitrate anions within the asymmetric unit balance the charges of the central metal ion, and are linked with two crystal water mol­ecules, forming a water–nitrate cyclic tetra­meric unit [O⋯O = 2.813 (2) to 3.062 (2) Å]. In an isolated mol­ecule, the fluoro­phenyl rings of one ligand are stacked with the central ring of the other ligand via π–π inter­actions, with the closest centroid-to-plane distances being 3.359 (6), 3.408 (5), 3.757 (6) and 3.659 (5) Å.

In the title compound, C29H23ClN2O, the 5-chloro­phenol ring and the imidazole ring are nearly coplanar, with a dihedral angle of 15.76 (9)° between them. The ethyl­phenyl ring and the two phenyl rings subtend angles of 71.09 (7), 43.95 (5) and 36.53 (9)°, respectively, with the imidazole plane. An intra­molecular O—H⋯N hydrogen bond supports the mol­ecular conformation, and an inter­molecular C—H⋯O inter­action, originating from an ortho-phenyl H atom, stabilizes the packing arrangement. In addition, a weak C—H⋯π inter­action, also involving an ortho-phenyl H atom, is observed.

In the title compound, C12H9ClN2O, the dihedral angle between the aromatic rings is 1.78 (4)° and an intra­molecular O—H⋯N hydrogen bond closes an S(6) ring. In the crystal, C—H⋯O and C—H⋯N hydrogen bonds connect the mol­ecules into [001] chains.

In the title complex, [NiCl2(C12H9N3)2]·H2O, a divalent nickel atom is coordinated by two 2-(pyridin-2-yl)-1H-benzimidazole ligands in a slightly distorted octa­hedral environment defined by four N donors of two N,N'-chelating ligands, along with two cis-oriented anionic chloride donors. The title complex crystallized with a water mol­ecule disordered over two positions. In the crystal, a combination of O—H⋯Cl, O—H.·O and N—H⋯Cl hydrogen bonds, together with C—H⋯O, C—H⋯Cl and C—H⋯π inter­actions, links the complex mol­ecules and the water mol­ecules to form a supra­molecular three-dimensional framework. The title complex is isostructural with the cobalt(II) dichloride complex reported previously [Das et al. (2011). Org. Biomol. Chem. 9, 7097–7107].

In the title compound, C16H21N3O4, the 1,4-di­hydro­pyridine ring adopts a flattened boat conformation, with the imidazole substituent in an axial orientation [dihedral angle between ring planes = 82.9 (6)°]. In the crystal structure, pairs of N—H⋯O and N—H⋯N hydrogen bonds with graph-set notation R22(14) connect the mol­ecules into chains running along the c-axis direction.

The title compound, C25H22N2O2Se, crystallizes in the space group P21/c with one mol­ecule in the asymmetric unit. The compound was synthesized by the addition of phenyl­selenyl bromide to a cyanamide. The phenyl­selenyl portion and the cyano group, as well as the ketone functional group in the cyclo­hexa-2,5-dien-1-one portion of the structure, are disordered, with occupancy factors of 0.555 (14) and 0.445 (14).

The structure of the title salt, C6H10N22+·2C7H7O3S−, consists of a unique benzene-1,2-diaminium dication charge balanced by a pair of crystallographically independent 4-methyl­benzene-1-sulfonate anions. The cations and anions are inter­linked by several N—H⋯O hydrogen bonds.

Caesium tetra­fluorido­bromate(III), CsBrF4, was crystallized in form of small blocks by melting and recrystallization. The crystal structure of CsBrF4 was redetermined from single-crystal X-ray diffraction data. In comparison with a previous study based on powder X-ray diffraction data [Ivlev et al. (2013). Z. Anorg. Allg. Chem. 639, 2846–2850], bond lengths and angles were determined with higher precision, and all atoms were refined with anisotropic displacement parameters. It was confirmed that the structure of CsBrF4 contains two square-planar [BrF4]− anions each with point group symmetry mmm, and a caesium cation (site symmetry mm2) that is coordinated by twelve fluorine atoms, forming an anti­cubocta­hedron. CsBrF4 is isotypic with CsAuF4.

The title hemihydrate, C12H9N5·0.5H2O, was isolated from the condensation reaction of quinoline-2-carbaldehyde with 4-amino-4H-1,2,4-triazole. The Schiff base mol­ecule adopts an E configuration about the C=N bond and is approximately planar, with a dihedral angle between the quinoline ring system and the 1,2,4-triazole ring of 12.2 (1)°. In the crystal, one water mol­ecule bridges two Schiff base mol­ecules via O—H⋯N hydrogen bonds. The Schiff base mol­ecules are inter­connected by π–π stacking inter­actions [centroid-centroid distances of 3.7486 (7) and 3.9003 (7) Å] into columns along [1overline{1}0].

The structure of the title compound, H3O+·C2F6NO4S2−·C12H24O6 or [H3O+·C12H24O6][N(SO2CF3)2−], which is an ionic liquid with a melting point of 341–343 K, has been determined at 113 K. The asymmetric unit consists of two crystallographically independent 18-crown-6 mol­ecules, two hydro­nium ions and two bis­(tri­fluoro­methane­sulfon­yl)amide anions; each 18-crown-6 mol­ecule complexes with a hydro­nium ion. In one 18-crown-6 mol­ecule, a part of the ring exhibits conformational disorder over two sets of sites with an occupancy ratio of 0.533 (13):0.467 (13). One hydro­nium ion is complexed with the ordered 18-crown-6 mol­ecule via O—H⋯O hydrogen bonds with H2OH⋯OC distances of 1.90 (6)–2.19 (7) Å, and the other hydro­nium ion with the disordered crown mol­ecule with distances of 1.85 (6)–2.36 (6) Å. The hydro­nium ions are also linked to the anions via O—H⋯F hydrogen bonds. The crystal studied was found to be a racemic twin with a component ratio of 0.55 (13):0.45 (13).

In the extended structure of the title mol­ecular salt, C6H9N2+·C7H7O3S−, the cations and anions are linked by N—H⋯O hydrogen bonds to generate [010] chains.

In the title compound [systematic name: 5-methyl-1,3-bis­(2-oxoprop­yl)pyrimidine-2,4(1H,3H)-dione], C11H14N2O4, the two 2-oxopropyl groups are nearly perpendicular to the planar thymine unit. One methyl group of oxopropyl substituent is disordered. In the crystal, C—H⋯O inter­actions help to connect the mol­ecules into (001) layers.

The title compound, (C15H23N2)2[MnBr4], comprises two N-adamantyl-N'-ethyl­imidazolium cations and one tetra­hedral [MnBr4]2− anion. Next to Coulombic inter­actions, weak hydrogen bonds of the type C—H⋯Br consolidate the crystal packing, building up a three-dimensional network.

The structure of the tertiary amine tris­(1H-benzimidazol-2-ylmeth­yl)amine (C24H21N7, abbreviated ntb) has been previously reported twice as solvates, namely the monohydrate and the aceto­nitrile–methanol–water (1/0.5/1.5) solvate, both with the tripodal conformation formed via multiple hydrogen bonds. Now, we report the tri­methanol adduct, ntb·3CH3OH, where the amine has the stair conformation featuring one benzimidazole group oriented in the opposite direction from the other two. The asymmetric unit contains one-half amine, completed through the mirror plane m in space group Pmn21 to form the ntb mol­ecule, with the H atom for each imidazole moiety equally disordered between both N sites available in the imidazole ring. The asymmetric unit also contains one and a half methanol mol­ecules, one being placed in general position with the hy­droxy H atom disordered over two sites with occupancy ratio 1:1, while the other lies on the m mirror plane, and has thus its hy­droxy H atom disordered by symmetry. As in the previously reported solvates, all imine and amine groups of the ntb mol­ecules and the methanol mol­ecules are involved in N—H⋯O and O—H⋯N hydrogen bonds. In the title compound, however, the involved H atom is systematically a disordered H atom provided by an imidazole group or a methanol mol­ecule.

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.

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 crystal structure of (NH4)2V3O8 has been reported twice using single-crystal X-ray data [Theobald et al. (1984). J. Phys. Chem. Solids, 45, 581–587; Range et al. (1988). Z. Naturforsch. Teil B, 43, 309–317]. In both cases, the orientation of the ammonium cation in the asymmetric unit was poorly defined: in Theobald's study, the shape and dimensions were constrained for NH4+, while in Range's study, H atoms were not included. In the present study, we collected a highly redundant data set for this ternary oxide, at 0.61 Å resolution, using Ag Kα radiation. These accurate data reveal that the NH4+ cation is disordered by rotation around a non-crystallographic axis. The rotation axis coincides with one N—H bond lying in the mirror m symmetry element of space-group type P4bm, and the remaining H sites were modelled over two disordered positions, with equal occupancy. It therefore follows that the NH4+ cations filling the space available in the (001) layered structure formed by (V3O8)2– ions do not form strong N—H⋯O hydrogen bonds with the mixed-valent oxidovanadate(IV,V) anions. This feature could have consequences for the Li-ion inter­calation properties of this material, which is used as a cathode for supercapacitors.

The title compound {systematic name: N-[2-(5-meth­oxy-1H-indol-3-yl)eth­yl]-N-(prop-2-en-1-yl)prop-2-en-1-amine), C17H22N2O, has a single tryptamine mol­ecule in the asymmetric unit. The mol­ecules are linked by strong N—H⋯N hydrogen bonds into zigzag chains with graph-set notation C(7) along the [010] direction.

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 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 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, C15H13BrO2S, comprises three different substituents bound to a central (and chiral) methine-C atom, i.e. (4-bromo­phen­yl)sulfanyl, benzaldehyde and meth­oxy residues: crystal symmetry generates a racemic mixture. A twist in the mol­ecule is evident about the methine-C—C(carbon­yl) bond as evidenced by the O—C—C—O torsion angle of −20.8 (7)°. The dihedral angle between the bromo­benzene and phenyl rings is 43.2 (2)°, with the former disposed to lie over the oxygen atoms. The most prominent feature of the packing is the formation of helical supra­molecular chains as a result of methyl- and methine-C—H⋯O(carbon­yl) inter­actions. The chains assemble into a three-dimensional architecture without directional inter­actions between them. The nature of the weak points of contacts has been probed by a combination of Hirshfeld surface analysis, non-covalent inter­action plots and inter­action energy calculations. These point to the importance of weaker H⋯H and C—H⋯C inter­actions in the consolidation of 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 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 benzo­furan derivatives 2-amino-5-hy­droxy-4-(4-nitro­phen­yl)benzo­furan-3-carboxyl­ate (BF1), C19H18N2O6, and 2-meth­oxy­ethyl 2-amino-5-hy­droxy-4-(4-nitro­phen­yl)benzo­furan-3-carboxyl­ate (BF2), C18H16N2O7, recently attracted attention because of their promising anti­tumoral activity. BF1 crystallizes in the space group Poverline{1}. BF2 in the space group P21/c. The nitro­phenyl group is inclined to benzo­furan moiety with a dihedral angle between their mean planes of 69.2 (2)° in BF1 and 60.20 (6)° in BF2. A common feature in the mol­ecular structures of BF1 and BF2 is the intra­molecular N—H⋯Ocarbon­yl hydrogen bond. In the crystal of BF1, the mol­ecules are linked head-to-tail into a one-dimensional hydrogen-bonding pattern along the a-axis direction. In BF2, pairs of head-to-tail hydrogen-bonded chains of mol­ecules along the b-axis direction are linked by O—H⋯Ometh­oxy hydrogen bonds. In BF1, the butyl group is disordered over two orientations with occupancies of 0.557 (13) and 0.443 (13).

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].

In the title compound, the asymmetric unit comprises an N,N,N-trimethyl-1-(4-vinyl­phen­yl)methanaminium cation and a 4-vinyl­benzene­sulfonate anion, C12H18N+·C8H7O3S−. The salt has a polymerizable vinyl group attached to both the cation and the anion. The methanaminium and vinyl substituents on the benzene ring of the cation subtend angles of 86.6 (3) and 10.5 (9)° to the ring plane, while the anion is planar excluding the sulfonate O atoms. The vinyl substituent on the benzene ring of the cation is disordered over two sites with a refined occupancy ratio of 0.542 (11):0.458 (11). In the crystal, C—H⋯O hydrogen bonds dominate the packing and combine with a C—H⋯π(ring) contact to stack the cations and anions along the a-axis direction. Hirshfeld surface analysis of the salt and of the individual cation and anion components is also reported.

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.

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.

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 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.

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.

The asymmetric unit of the title compound, C15H21N3OS, comprises of two crystallographically independent mol­ecules (A and B). Each mol­ecule consists of a cyclo­hexane ring and a 2-hy­droxy-3-methyl­benzyl­idene ring bridged by a hydrazinecarbo­thio­amine unit. Both mol­ecules exhibit an E configuration with respect to the azomethine C=N bond. There is an intra­molecular O—H⋯N hydrogen bond in each mol­ecule forming an S(6) ring motif. The cyclo­hexane ring in each mol­ecule has a chair conformation. The benzene ring is inclined to the mean plane of the cyclo­hexane ring by 47.75 (9)° in mol­ecule A and 66.99 (9)° in mol­ecule B. The mean plane of the cyclo­hexane ring is inclined to the mean plane of the thio­urea moiety [N—C(=S)—N] by 55.69 (9) and 58.50 (8)° in mol­ecules A and B, respectively. In the crystal, the A and B mol­ecules are linked by N—H⋯S hydrogen bonds, forming `dimers'. The A mol­ecules are further linked by a C—H⋯π inter­action, hence linking the A–B units to form ribbons propagating along the b-axis direction. The conformation of a number of related cyclo­hexa­nehydrazinecarbo­thio­amides are compared to that of the title compound.

The title compound, C31H30N2S2O6, possesses crystallographically imposed twofold symmetry with the two C atoms of the central benzene ring and the C atom of its methyl substituent lying on the twofold rotation axis. The two dansyl groups are twisted away from the plane of methyl­phenyl bridging unit in opposite directions. The three-dimensional arrangement in the crystal is mainly stabilized by weak hydrogen bonds between the sulfonyl oxygen atoms and the hydrogen atoms from the N-methyl groups. Stacking of the dansyl group is not observed. From the DFT calculations, the HOMO–LUMO energy gap was found to be 2.99 eV and indicates n→π* and π→π* transitions within the mol­ecule.

The title compounds, 8-amino-6-methyl-3,4-diphenyl-1H-isochromen-1-one, C22H17NO2, (I), and 8-amino-3,4-diethyl-6-methyl-1H-isochromen-1-one, C14H17NO2, (II), are new isocoumarin derivatives in which the isochromene ring systems are planar. Compound II crystallizes with two independent mol­ecules (A and B) in the asymmetric unit. In I, the two phenyl rings are inclined to each other by 56.41 (7)° and to the mean plane of the 1H-isochromene ring system by 67.64 (6) and 44.92 (6)°. In both compounds, there is an intra­molecular N—H⋯O hydrogen bond present forming an S(6) ring motif. In the crystal of I, mol­ecules are linked by N—H⋯π inter­actions, forming chains along the b-axis direction. A C—H⋯π inter­action links the chains to form layers parallel to (100). The layers are then linked by a second C—H⋯π inter­action, forming a three-dimensional structure. In the crystal of II, the two independent mol­ecules (A and B) are linked by N—H⋯O hydrogen bonds, forming –A–B–A–B– chains along the [101] direction. The chains are linked into ribbons by C—H⋯π inter­actions involving inversion-related A mol­ecules. The latter are linked by offset π–π inter­actions [inter­centroid distances vary from 3.506 (1) to 3.870 (2) Å], forming a three-dimensional structure.

The title compound, 2-(methyl­amino)­cyclo­hepta-2,4,6-trien-1-one, C8H9NO, crystallizes in the monoclinic space group P21/c, with three independent mol­ecules in the asymmetric unit. The planarity of the mol­ecules is indicated by planes fitted through the seven ring carbon atoms. Small deviations from the planes, with an extremal r.m.s. deviation of 0.0345 Å, are present. In complexes of transition metals with similar ligands, the large planar seven-membered aromatic rings have shown to improve the stability of the complex. Two types of hydrogen-bonding inter­actions, C—H⋯O and N—H⋯O, are observed, as well as bifurcation of these inter­actions. The N—H⋯O inter­actions link mol­ecules to form infinite chains. The packing of mol­ecules in the unit cell shows a pattern of overlapping aromatic rings, forming column-like formations. π–π inter­actions are observed between the overlapping aromatic rings at 3.4462 (19) Å from each other.

The asymmetric unit of the title 1:1 solvate, C14H14N4O2·C6H6 [systematic name of the oxalamide mol­ecule: N,N'-bis­(pyridin-4-ylmeth­yl)ethanedi­amide], comprises a half mol­ecule of each constituent as each is disposed about a centre of inversion. In the oxalamide mol­ecule, the central C2N2O2 atoms are planar (r.m.s. deviation = 0.0006 Å). An intra­molecular amide-N—H⋯O(amide) hydrogen bond is evident, which gives rise to an S(5) loop. Overall, the mol­ecule adopts an anti­periplanar disposition of the pyridyl rings, and an orthogonal relationship is evident between the central plane and each terminal pyridyl ring [dihedral angle = 86.89 (3)°]. In the crystal, supra­molecular layers parallel to (10overline{2}) are generated owing the formation of amide-N—H⋯N(pyrid­yl) hydrogen bonds. The layers stack encompassing benzene mol­ecules which provide the links between layers via methyl­ene-C—H⋯π(benzene) and benzene-C—H⋯π(pyrid­yl) inter­actions. The specified contacts are indicated in an analysis of the calculated Hirshfeld surfaces. The energy of stabilization provided by the conventional hydrogen bonding (approximately 40 kJ mol−1; electrostatic forces) is just over double that by the C—H⋯π contacts (dispersion forces).

The title salt, C16H15ClN3S+·Br−, is isotypic with (E)-3-[(4-fluoro­benzyl­idene)amino]-5-phenyl­thia­zolidin-2-iminium bromide [Khalilov et al. (2019). Acta Cryst. E75, 662–666]. In the cation of the title salt, the atoms of the phenyl ring attached to the central thia­zolidine ring and the atom joining the thia­zolidine ring to the benzene ring are disordered over two sets of sites with occupancies of 0.570 (3) and 0.430 (3). The major and minor components of the disordered thia­zolidine ring adopt slightly distorted envelope conformations, with the C atom bearing the phenyl ring as the flap atom. In the crystal, centrosymmetrically related cations and anions are linked into dimeric units via N—H⋯Br hydrogen bonds, which are further connected by weak C—H⋯Br contacts into chains parallel to the a axis. Furthermore, not existing in the earlier report of (E)-3-[(4-fluoro­benzyl­idene)amino]-5-phenyl­thia­zolidin-2-iminium bromide, C—H⋯π inter­actions and π–π stacking inter­actions [centroid-to-centroid distance = 3.897 (2) Å] between the major components of the disordered phenyl ring contribute to the stabilization of the mol­ecular packing. Hirshfeld surface analysis and two-dimensional fingerprint plots indicate that the most important contributions for the crystal packing are from H⋯H (30.5%), Br⋯H/H⋯Br (21.2%), C⋯H/H⋯C (19.2%), Cl⋯H/H⋯Cl (13.0%) and S⋯H/H⋯S (5.0%) inter­actions.

The monocation product of the oxidative condensation–cyclization between two mol­ecules of pyridine-2-carbaldehyde and one mol­ecule of CH3NH2·HCl in methanol, 2-methyl-3-(pyridin-2-yl)imidazo[1,5-a]pyridinium, was isolated in the presence of metal ions as bis­[2-methyl-3-(pyridin-2-yl)imidazo[1,5-a]pyridin-2-ium] tetra­iodo­cadmate, (C13H12N3)2[CdI4], (I), and the mixed chloride/nitrate salt, bis­[2-methyl-3-(pyridin-2-yl)imidazo[1,5-a]pyridin-2-ium] 1.5-chlor­ide 0.5-nitrate trihydrate, 2C13H12N3+·1.5Cl−·0.5NO3−·3H2O, (II). Hybrid salt (I) crystallizes in the space group P21/n with two [L]2[CdI4] mol­ecules in the asymmetric unit related by pseudosymmetry. In the crystal of (I), layers of organic cations and of tetra­halometallate anions are stacked parallel to the ab plane. Anti­parallel L+ cations disposed in a herring-bone pattern form π-bonded chains through aromatic stacking. In the inorganic layer, adjacent tetra­hedral CdI4 units have no connectivity but demonstrate close packing of iodide anions. In the crystal lattice of (II), the cations are arranged in stacks propagating along the a axis; the one-dimensional hydrogen-bonded polymer built of chloride ions and water mol­ecules runs parallel to a column of stacked cations.

The di-substituted acetyl­ene residue in the title compound, C11H11NO3, is capped at either end by di-methyl­hydroxy and 4-nitro­benzene groups; the nitro substituent is close to co-planar with the ring to which it is attached [dihedral angle = 9.4 (3)°]. The most prominent feature of the mol­ecular packing is the formation, via hy­droxy-O—H⋯O(hy­droxy) hydrogen bonds, of hexa­meric clusters about a site of symmetry overline{3}. The aggregates are sustained by 12-membered {⋯OH}6 synthons and have the shape of a flattened chair. The clusters are connected into a three-dimensional architecture by benzene-C—H⋯O(nitro) inter­actions, involving both nitro-O atoms. The aforementioned inter­actions are readily identified in the calculated Hirshfeld surface. Computational chemistry indicates there is a significant energy, primarily electrostatic in nature, associated with the hy­droxy-O—H⋯O(hy­droxy) hydrogen bonds. Dispersion forces are more important in the other identified but, weaker inter­molecular contacts.