In the title compound, C16H19NSe, the dihedral angle between the benzene rings is 66.49 (12) and a weak intra­molecular N—H⋯Se hydrogen bond generates an S(6) ring. In the crystal, weak N—H⋯N hydrogen bonds link the mol­ecules into [100] chains.

The title salt, C24H27N2OS+·BF4−, was prepared by an alkyl­ation at the amino N atom attached to the sulfur atom of the corresponding sulfodi­imide. The configuration around the sulfur atom is a slightly distorted tetra­hedral geometry with two S—N bonds and two S—C bonds. The lengths of the S—N(di­ethyl­amine) and S=N(m-methyl­benzoyl­imine) bonds are 1.619 (2) and 1.551 (2) Å, respectively. The two N—S—N—C(eth­yl) and the N—S—N—C(m-methyl­benzoyl­imine) torsion angles are −85.43 (3), 58.94 (17) and 62.03 (16)°, respectively. The dihedral angle between the two phenyl rings is 84.03 (14)°. In the crystal, C—H⋯F hydrogen bonds link the cation and anion, forming a three-dimensional network.

The title tetra­nuclear stannoxane, [Sn4(C6H5)8(C6H4NO3)4O2]·1.5CHCl3·solvent, crystallized with two independent complex mol­ecules, A and B, in the asymmetric unit together with 1.5 mol­ecules of chloro­form. There is also a region of disordered electron density, which was corrected for using the SQUEEZE routine [Spek (2015). Acta Cryst. C71, 9–18]. The oxo-tin core of each complex is in a planar `ladder' arrangement and each Sn atom is fivefold SnO3C2 coordinated, with one tin centre having an almost perfect square-pyramidal coordination geometry, while the other three Sn centres have distorted shapes. In the crystal, the complex mol­ecules are arranged in layers, composed of A or B complexes, lying parallel to the bc plane. The complex mol­ecules are linked by a number of C—H⋯O hydrogen bonds within the layers and between the layers, forming a supra­molecular three-dimensional structure.

The asymmetric unit of the title compound, [Fe(C5H5)(C12H7ClNO)], consists of one ferrocenyl group bonded to chloro­benzo[d]oxazole. The conformation of the ferrocenyl moiety is slightly away from eclipsed. The bond angles between the 5-chloro-benzoxazole and ferrocenyl fragments are N—C—C = 127.4 (7)° and O—C—C = 116.8 (7)°. The benzo[d]oxazole ring is planar (r.m.s. deviation = 0.0042 Å) and makes an angle of 11.3 (4)° with the cyclo­penta­dienyl ring attached to it. The crystal packing is characterized by inter­molecular π–π contacts, resulting in chain formation along the b-axis direction. The centroid-to-centroid distance between the six- and five-membered rings is 3.650 (5) Å. Together with a C—H⋯π inter­action, these inter­molecular contacts form laminar arrays along the ac plane.

The synthesis and crystal structure of the title PtII complex, [Pt(C23H16N)Cl(CH3CN)], based on the C,N-chelating 2,4,6-tri­phenyl­pyridine as the primary ligand, is described. The central PtII atom is in a distorted square-planar coordination environment. In the crystal, mol­ecules are arranged via a metallophilic inter­action between platinum atoms with a Pt⋯Pt contact of 7.052 (2) Å. In addition, a π–π inter­action occurs.

The title two-dimensional coordination polymer, [Zn(C6H5PO3)]n, was synthesized serendipitously by reacting a tetra­phospho­nate cavitand Tiiii[C3H7, CH3, C6H5] and Zn(CH3COO)2·2H2O in a DMF/H2O mixture. The basic conditions of the reaction cleaved the phospho­nate bridges at the upper rim of the cavitand, making them available for reaction with the zinc ions. The coordination polymer can be described as an inorganic layer in which zinc coordinates the oxygen atoms of the phospho­nate groups in a distorted tetra­hedral environment, while the phenyl groups, which are statistically disordered over two orientations, point up and down with respect to the layer. The layers inter­act through van der Waals inter­actions. The crystal studied was refined as a two-component twin.

The molecular salt, C23H26N2O2+·Cl−, was obtained from 1-isobutyl-8,9-dimeth­oxy-3-phenyl-5,6-di­hydro­imidazo[5,1-a]iso­quinoline, which was synthesized by cyclo­condensation of α-benzoyl­amino-γ-methyl-N-[2-(3,4-di­meth­oxy­phen­yl)eth­yl]valeramide in the presence of phosphoryl chloride. The tetra­hydro­pyridine ring adopts a twist–boat conformation. In the crystal structure, centrosymmetric dimers are formed by N—H⋯Cl and C—H⋯Cl hydrogen bonds.

In the title compound, C22H25NO5·H2O, the ten-membered ring displays an approximate chair–chair conformation, whereas the five-membered furan ring has an envelope conformation, with the C atom of the methine group adjacent to the spiro C atom as the flap. The isoxazole ring is almost planar and its plane is slightly inclined to the plane of the attached phenyl ring. The mean plane of the furan ring is nearly perpendicular to that of the isoxazole ring, as indicated by the dihedral angle between them of 89.39 (12)°. In the crystal, the organic mol­ecules are linked into [010] chains by O—H⋯O hydrogen bonds. The water mol­ecule forms O—H⋯O and O—H⋯N hydrogen bonds and a weak C—H⋯O inter­action is also observed. Together, these lead to a three-dimensional network.

The title magnesium complex, [Mg(C21H20NO2)2(C4H8O)]n, exhibits two N,O-bidentate 2-(di­methyl­amino)-α,α-di­phenyl­benzene­methano­late ligands, form­ing two six-membered chelate rings. The distorted square-pyramidal coordination sphere of the MgII atom is completed by the O atom of a tetra­hydro­furan ligand, with its O atom in the apical position. The O and N atoms are in a mutual trans arrangement. Except for two C—H⋯π inter­actions, no significant inter­molecular inter­actions are observed in the crystal.

The title compound, C26H22O2P+·PF6−·C4H7O, crystallizes as a cation-anion pair with a single solvent mol­ecule in the asymmetric unit. Hydrogen bonding occurs between the carb­oxy­lic acid group on the cation and the oxygen atom of the solvent mol­ecule. Longer hydrogen-bonding inter­actions are observed between fluorine atoms of the anion and H atoms on the phenyl rings of the cation.

The title compound, C22H22O5, crystallizes with two mol­ecules in the asymmetric unit, one of which shows disorder of its ethyl acetate group over two sets of sites in a 0.880 (2):0.120 (2) ratio. The C≡C distances in the two mol­ecules are almost the same [1.1939 (16) and 1.199 (2) Å], but the Csp3—C≡C angles differ somewhat [175.92 (12) and 172.53 (16)°]. In the crystal, several weak C—H⋯O inter­actions are seen.

The structure of the title compound, [Os(C6HF4S)4{P(C6H5)3}], has been previously reported [Arroyo et al. (1994). J. Chem. Soc. Dalton Trans. pp. 1819–1824], in the space group Poverline{1}. We have now obtained a monoclinic polymorph for this compound, crystallized from ethanol, while the previous form was obtained from a hexa­ne/chloro­form mixture. The mol­ecular structure is based on a trigonal–bipyramidal OsIV coordination geometry, close to that observed previously in the triclinic form.

The crystal structure of the benzene monosolvate of the well known organic diphosphite ligand BIPHEPHOS, C46H44O8P2·C6H6, is reported for the first time. Single crystals of BIPHEPHOS were obtained from a benzene solution after layering with n-heptane at room temperature. One specific property of this type of diphosphite structure is the twisting of the biphenyl units. In the crystal, C—H⋯π contacts and π–π stacking inter­actions [centroid-to-centroid distance = 3.8941 (15) Å] are observed.

In the title compound, C29H26ClNO4, the di­hydro­pyridine ring adopts a shallow boat conformation. The mean plane of the di­hydro­pyridine ring (all atoms) subtends dihedral angles of 66.54 (1), 73.71 (1) and 79.47 (1)° with the two phenyl rings and the chloro­phenyl ring, respectively. In the crystal, N—H⋯O hydrogen bonds link the mol­ecules into [001] chains.

In the title compound, C18H16N2O2, the dihedral angle between the pyrrole rings is 79.47 (9)°, with the N—H groups approximately orthogonal (H—N⋯N—H pseudo torsion angle = −106°). In the crystal, N—H⋯O hydrogen bonds link the mol­ecules into [11overline{1}] chains. A C—H⋯O inter­action is also observed.

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.

The title compound, [Bi(C9H6NS2)3], was prepared by reacting BiCl3 and 2-mercapto-4-phenyl­thia­zole (LH) at room temperature in a stoichiometric ratio of 1:4. The mol­ecular structure reveals a slightly distorted square-pyramidal environment around the BiIII atom. Two of the three monoanionic ligands L− coordinate in an N,S-bidentate mode, while one shows a monodentate mode through an S atom. There are no significant inter­molecular inter­actions present in the crystal.

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 title compound, C20H18N4O2, known as bis­pyrazolone, was crystallized from dimethyl sulfoxide. The structure has ortho­rhom­bic (Pbca) symmetry at 150 K, and displays both intra- and inter­molecular hydrogen bonding through C—H⋯O and N—H⋯O contacts, respectively. None of the phenyl and pyrazolone rings in the mol­ecule are coplanar. The dihedral angle between the pyrazolone rings is 66.18 (5)°.

In the title compound, C21H20BrNO4S, a key inter­mediate in the synthesis of the widely used β-lactamase inhibitor tazobactam, the five-membered thia­zolidine ring adopts an envelope conformation and the four-membered azetidine ring is in a distorted planar conformation. The crystal structure features C—H⋯O hydrogen bonds and a weak C—H⋯π inter­action.

The tricyclic core in the title compound, C26H34O4Si2, shows disorder of the furan ring and deviates slightly from planarity, with the largest displacement from the least-squares plane [0.166 (2) Å] for the major disordered part of the methine C atom. To this C atom the likewise disordered vinyl group is attached, lying nearly perpendicular to the tricyclic core. In the crystal, mutual C—H⋯π inter­actions between the methine group of the furan ring and the central ring of the tricyclic core of an adjacent mol­ecule lead to inversion-related dimers.

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.

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, 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 compounds, C24H22O6 (I) and C24H22O6 (II), each crystallize with half a mol­ecule in the asymmetric unit. The whole mol­ecule of compound (I) is generated by twofold rotation symmetry, the twofold axis bis­ecting the central benzene ring. The whole mol­ecule of compound (II) is generated by inversion symmetry, the central benzene ring being located on an inversion center. In (I), the outer benzene rings are inclined to each other by 59.96 (10)° and by 36.74 (9)° to the central benzene ring. The corresponding dihedral angles in (II) are 0.0 and 89.87 (12)°. In the crystal of (I), mol­ecules are linked by C—H⋯O hydrogen bonds and C—H⋯π inter­actions, forming ribbons propagating along the [10overline{1}] direction. In the crystal of (II), mol­ecules are linked by C—H⋯O hydrogen bonds, forming a supra­molecular framework. The Hirshfeld surface analyses indicate that for both compounds the H⋯H contacts are the most significant, followed by O⋯H/H⋯O and C⋯H/H⋯C contacts.

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.

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 synthesis and crystal structures of a series of 6-aryl­fuvlenes (fulvene is 5-methyl­idene­cyclo­penta-1,3-diene) with varying methyl­ation patterns on the 6-phenyl substituent are reported, namely 6-(3-methyl­phen­yl)-1,3-di­phenyl­fulvene (C25H20), 6-(4-methyl­phen­yl)-1,3-di­phenyl­fulvene (C25H20), 6-mesityl-3-di­phenyl­fulvene (C27H24) and 6-(2,3,4,5,6-penta­methyl­phen­yl)-1,3-di­phenyl­fulvene (C29H28). The bond lengths are typical of those observed in related fulvenes. A network of C—H⋯π ring inter­actions consolidates the packing in each structure.

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.

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.

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, 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 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.

Reductive cyclization of 1,3,5-triphenyl- and 3-(2-meth­oxy­phen­yl)-1,5-di­phenyl­pentane-1,5-diones by zinc in acetic acid medium leads to the formation of 1,2,4-tri­phenyl­cyclo­pentane-1,2-diol [1,2,4-Ph3C5H5-1,2-(OH)2, C23H22O2, (I)] and 4-(2-meth­oxy­phen­yl)-1,2-di­phenyl­cyclo­pentane-1,2-diol [4-(2-MeOC6H4)-1,2-Ph2C5H5-1,2-(OH)2, C24H24O3, (II)]. Their single crystals have been obtained by crystallization from a THF/hexane solvent mixture. Diols (I) and (II) crystallize in ortho­rhom­bic (Pbca) and triclinic (Poverline{1}) space groups, respectively, at 150 K. Their asymmetric units comprise one [in the case of (I)] and three [in the case of (II)] crystallographically independent mol­ecules of the achiral (1R,2S,4r)-diol isomer. Each hydroxyl group is involved in one intra­molecular and one inter­molecular O—H⋯O hydrogen bond, forming one-dimensional chains. Compounds (I) and (II) have been used successfully as precatalyst activators for the ring-opening polymerization of ∊-caprolactone.

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.

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.

In the title polymeric complex, {[Fe(CN)2(C10H8N2)2(H2O)2][Au(CN)2]}n, the FeII ion, which is located on a twofold rotation axis, has a slightly distorted FeN4O2 octa­hedral geometry. It is coordinated by two phenyl­pyrazine mol­ecules, two water mol­ecules and two di­cyano­aurate anions, the Au atom also being located on a second twofold rotation axis. In the crystal, the coordinated di­cyano­aurate anions bridge the FeII ions to form polymeric chains propagating along the b-axis direction. In the crystal, the chains are linked by Owater—H⋯Ndi­cyano­aurate anions hydrogen bonds and aurophillic inter­actions [Au⋯Au = 3.5661 (3) Å], forming layers parallel to the bc plane. The layers are linked by offset π–π stacking inter­actions [inter­centroid distance = 3.643 (3) Å], forming a supra­molecular metal–organic framework.

In the title mol­ecule, C17H23NO2, the di­hydro­indole portion is planar (r.m.s. deviation = 0.0157 Å) and the nonyl substituent is in an `extended' conformation. In the crystal, the nonyl chains inter­calate and the di­hydro­indole­dione units are associated through C—H⋯O hydrogen bonds to form micellar blocks. Based on the Hirshfeld surface analysis, the most important inter­molecular inter­action is the H⋯H inter­action.

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 reaction of 2-methyl­thio-5-amino-1,3,4-thia­diazole (Me-SNTD; C3H5N3S2) with copper(II) acetate monohydrate [Cu(OAc)2·H2O; C4H8CuO5] resulted in the formation of the title binuclear compound, [Cu2(C2H3O2)4(C3H5N3S2)2] or [Cu2(OAc)4(Me-SNTD)2]. The structure has triclinic (P overline{1}) symmetry with a crystallographic inversion centre located at the midpoint of the line connecting the Cu atoms in the dimer. These two Cu atoms of the dimer [Cu⋯Cu = 2.6727 (6) Å] are held together by four carboxyl­ate groups. Each Cu atom is further coordinated to the N atom of an Me-SNTD mol­ecule and exhibits a Jahn–Teller-distorted octa­hedral geometry. The dimers are connected into infinite chains by hydrogen bonds between the NH (Me-SNTD) and the carboxyl­ate groups of neighbouring mol­ecules, generating an R22(12) ring motif. The mol­ecules are further linked by C—H⋯π inter­actions between the thia­diazole rings and the methyl groups of the acetate units.

The crystal of 6-(3-nitro­phen­yl)-7-phenyl-5-thia-7-aza­spiro­[2.6]nonan-8-one (1), C19H18N2O3S, has monoclinic (P21/n) symmetry while that of its isomer 6-(4-nitro­phen­yl)-7-phenyl-5-thia-7-aza­spiro­[2.6]nonan-8-one (2), has ortho­rhom­bic (Pca21) symmetry: compound 1 has two mol­ecules, A and B, in the asymmetric unit while 2 has one. In all three mol­ecules, the seven-membered thia­zepan ring exhibits a chair conformation with Q2 and Q3 values (Å) of 0.521 (3), 0.735 (3) and 0.485 (3), 0.749 (3) in 1 and 0.517 (5), 0.699 (5) in 2. In each structure, the phenyl rings attached to adjacent atoms of the thia­zepan ring have inter­planar angles ranging between 41 and 47°. Except for the nitro groups, the three mol­ecules have similar conformations when overlayed in pairs. Both crystal structures are consolidated by C—H⋯O hydrogen bonds.

The sterically hindered silicon compound 2-methyl-1,1,2,3,3-penta­phenyl-2-sila­propane, C33H30Si (I), was prepared via the reaction of two equivalents of di­phenyl­methyl­lithium (benzhydryllithium) and di­chloro­methyl­phenyl­silane. This bis­benzhydryl-substituted silicon compound was then reacted with tri­fluoro­methane­sulfonic acid, followed by hydrolysis with water to give the silanol 2-methyl-1,1,3,3-tetra­phenyl-2-silapropan-2-ol, C27H26OSi (II). Key geometric features for I are the Si—C bond lengths that range from 1.867 (2) to 1.914 (2) Å and a τ4 descriptor for fourfold coordination around the Si atom of 0.97 (indicating a nearly perfect tetra­hedron). Key geometric features for compound II include Si—C bond lengths that range from 1.835 (4) to 1.905 (3) Å, a Si—O bond length of 1.665 (3) Å, and a τ4 descriptor for fourfold coordination around the Si atom of 0.96. In compound II, there is an intra­molecular C—H⋯O hydrogen bond present. In the crystal of I, mol­ecules are linked by two pairs of C—H⋯π inter­actions, forming dimers that are linked into ribbons propagating along the b-axis direction. In the crystal of II, mol­ecules are linked by C—H⋯π and O—H⋯π inter­actions that result in the formation of ribbons that run along the a-axis direction.

In this paper, we describe the synthesis of a new di­hydro-2H-pyridazin-3-one derivative. The mol­ecule, C18H16N2O, is not planar; the benzene and pyridazine rings are twisted with respect to each other, making a dihedral angle of 11.47 (2)°, and the toluene ring is nearly perpendicular to the pyridazine ring, with a dihedral angle of 89.624 (1)°. The mol­ecular conformation is stabilized by weak intra­molecular C—H⋯N contacts. In the crystal, pairs of N—H⋯O hydrogen bonds link the mol­ecules into inversion dimers with an R22(8) ring motif. The inter­molecular inter­actions were investigated using Hirshfeld surface analysis and two-dimensional (2D) fingerprint plots, revealing that the most important contributions for the crystal packing are from H⋯H (56.6%), H⋯C/C⋯H (22.6%), O⋯H/H⋯O (10.0%) and N⋯C/C⋯N (3.5%) inter­actions.