Synthesis and crystal structure of 2-(1,3-dithietan-2-yl-idene)cyclo-hexane-1,3-dione.

The title compound, C8H8O2S2, contains a cyclo-hexane-1,3-dione ring, which has a twist-boat conformation. The C2S2 ring is close to planar (r.m.s. deviation = 0.023 Å) and the dihedral angle between the mean planes of the cyclo-hexane and 1,3-dithietane rings is 9.1 (3)°. Short intra-molecular S⋯O contacts occur [2.719 (5) and 2.740 (5) Å]. In the crystal, the mol-ecules are linked by weak C-H⋯S hydrogen bonds and short [3.165 (5) Å] S⋯O contacts, forming (010) layers. The prevalence of these inter-actions is illustrated by an analysis of the three-dimensional Hirshfeld surface and by two-dimensional fingerprint plots.

Crystal structure and Hirshfeld surface analysis of 1-[(E)-2-(5-chloro-2-hy-droxy-phen-yl)hydrazin-1-yl-idene]naphthalen-2(1H)-one.

The title compound, C16H11ClN2O2, was obtained by diazo-tization of 2-amino-4-chloro-phenol followed by a coupling reaction with ß-naphthol. There are two mol-ecules (A and B) in the asymmetric unit. The crystal structure features only one type of inter-molecular inter-action, that is strong hydrogen bonds involving the hydroxyl group. The naphthol and phenol fragments attached to the C=N-N- moiety exhibit an s-trans conformation. In addition, those fragments are almost coplanar, subtending a dihedral angle of 13.11 (2)° in mol-ecule A and 10.35 (2)° in mol-ecule B. A Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from H⋯H (32.1%), C⋯H/H⋯C (23.1%), Cl⋯H/H⋯Cl (15.2%), O⋯H/H⋯O (12.8%) and C⋯C (9%) contacts.

Crystal structure, characterization and Hirshfeld analysis of bis-{(E)-1-[(2,4,6-tri-bromo-phen-yl)diazen-yl]naphthalen-2-olato}copper(II) dimethyl sulfoxide monosolvate.

In the title compound, [Cu(C16H8Br3N2O)2]·C2H6OS, the CuII atom is tetra-coordinated in a square-planar coordination, being surrounded by two N atoms and two O atoms from two N,O-bidentate (E)-1-[(2,4,6-tri-bromo-phen-yl)diazen-yl]naphthalen-2-olate ligands. The two N atoms and two O atoms around the metal center are trans to each other, with an O-Cu-O bond angle of 177.90 (16)° and a N-Cu-N bond angle of 177.8 (2)°. The average distances between the CuII atom and the coordinated O and N atoms are 1.892 (4) and 1.976 (4) Å, respectively. In the crystal, complexes are linked by C-H⋯O hydrogen bonds and by π-π inter-actions involving adjacent naphthalene ring systems [centroid-centroid distance = 3.679 (4) Å]. The disordered DMSO mol-ecules inter-act weakly with the complex mol-ecules, being positioned in the voids left by the packing arrangement of the square-planar complexes. The DMSO solvent mol-ecule is disordered over two positions with occupancies of 0.70 and 0.30.

Crystal structure and Hirshfeld surface analysis of (2E,2'E)-1,1'-[seleno-bis-(4,1-phenyl-ene)]bis-[3-(4-chloro-phen-yl)prop-2-en-1-one].

In the title com-pound, C30H20Cl2O2Se, the C-Se-C angle is 99.0 (2)°, with the dihedral angle between the planes of the attached benzene rings being 79.1 (3)°. The average endocyclic angles (Se-C-C) facing the Se atom are 122.1 (5) and 122.2 (5)°. The Se atom is essentially coplanar with the attached benzene rings, deviating by 0.075 (1) and 0.091 (1) Å. In the two phenyl-ene(4-chloro-phen-yl)prop-2-en-1-one units, the benzene rings are inclined to each other by 44.6 (3) and 7.8 (3)°. In the crystal, the mol-ecules stack up the a axis, forming layers parallel to the ac plane. There are no significant classical inter-molecular inter-actions present. Hirshfeld surface analysis, two-dimensional fingerprint plots and the mol-ecular electrostatic potential surface were used to analyse the crystal packing. The Hirshfeld surface analysis suggests that the most significant contributions to the crystal packing are by C⋯H/H⋯C contacts (17.7%).

Crystal structures of a copper(II) and the isotypic nickel(II) and palladium(II) complexes of the ligand (E)-1-[(2,4,6-tri-bromo-phen-yl)diazen-yl]naphthalen-2-ol.

In the copper(II) complex, bis-{(E)-1-[(2,4,6-tri-bromo-phen-yl)diazen-yl]naph-thalen-2-olato}copper(II), [Cu(C16H8Br3N2O)2], (I), the metal cation is coord-inated by two N atoms and two O atoms from two bidentate (E)-1-[(2,4,6-tri-bromo-phen-yl)diazen-yl]naphthalen-2-olate ligands, forming a slightly distorted square-planar environment. In one of the ligands, the tri-bromo-benzene ring is inclined to the naphthalene ring system by 37.4 (5)°, creating a weak intra-molecular Cu⋯Br inter-action [3.134 (2) Å], while in the other ligand, the tri-bromo-benzene ring is inclined to the naphthalene ring system by 72.1 (6)°. In the isotypic nickel(II) and palladium(II) complexes, namely bis-{(E)-1-[(2,4,6-tri-bromo-phen-yl)diazen-yl]naphthalen-2-olato}nickel(II), [Ni(C16H8Br3N2O)2], (II), and bis-{(E)-1-[(2,4,6-tri-bromo-phen-yl)diazen-yl]naphthalen-2-olato}palladium(II), [Pd(C16H8Br3N2O)2], (III), respectively, the metal atoms are located on centres of inversion, hence the metal coordination spheres have perfect square-planar geometries. The tri-bromo-benzene rings are inclined to the naphthalene ring systems by 80.79 (18)° in (II) and by 80.8 (3)° in (III). In the crystal of (I), mol-ecules are linked by C-H⋯Br hydrogen bonds, forming chains along [010]. The chains are linked by C-H⋯π inter-actions, forming sheets parallel to (011). In the crystals of (II) and (III), mol-ecules are linked by C-H⋯π inter-actions, forming slabs parallel to (10-1). For the copper(II) complex (I), a region of disordered electron density was corrected for using the SQUEEZE routine in PLATON [Spek (2015 ▸). Acta Cryst. C71, 9-18]. The formula mass and unit-cell characteristics of the disordered solvent mol-ecules were not taken into account during refinement.

Crystal structure of bis-{1-[(E)-(2-meth-oxy-phen-yl)diazen-yl]naphthalen-2-olato-κ(3) O,N (2),O'}copper(II) containing an unknown solvate.

The title complex, [Cu(C17H13N2O2)2], crystallizes with two independent mol-ecules in the asymmetric unit. Each Cu(II) atom has a distorted ocahedral coordination environment defined by two N atoms and four O atoms from two tridentate 1-[(E)-(2-meth-oxy-phen-yl)diazen-yl]naphthalen-2-olate ligands. In the crystal, the two mol-ecules are linked via weak C-H⋯O hydrogen bonds which in turn stack parallel to [010]. A region of disordered electron density, most probably disordered methanol solvent molecules, was corrected for using the SQUEEZE routine in PLATON [Spek (2015). Acta Cryst. C71, 9-18]. Their formula mass and unit-cell characteristics were not taken into account during refinement.

Crystal structure of bis-{µ-1-[(E)-(3-meth-oxy-phen-yl)diazen-yl]naphthalen-2-olato-κ(3) N (2),O:O}bis-({1-[(E)-(3-meth-oxy-phen-yl)diazen-yl]naphthalen-2-olato-κ(2) N (2),O}copper(II)).

The title dinuclear Cu(II) complex, [Cu2(C17H13N2O2)4], is located on an inversion centre. The Cu(II) atoms are each five-coordinated in a distorted square-pyramidal geometry by two N atoms and two O atoms from two bidentate ligands and one bridging O atom from another ligand. In the dinuclear complex, the Cu⋯Cu separation is 3.366 (3) Å. In the crystal, complex mol-ecules are linked via weak C-H⋯O hydrogen bonds, forming a layer parallel to (-101).

(E)-1-[(2,4,6-Tri-bromo-phen-yl)diazen-yl]naphthalen-2-ol.

The title azo mol-ecule, C16H9Br3N2O, adopts a trans conformation with respect to the azo N=N double bond. An intra-molecular O-H⋯N hydrogen bond forms an S(6) ring motif. The dihedral angle between the naphthalene ring system and the benzene ring is 33.80 (16)°. In the crystal, mol-ecules are stacked in columns along the a axis by π-π inter-actions [centroid-centroid distances = 3.815 (3) and 3.990 (3) Å].

1-[(E)-2-(2-Hy-droxy-5-methyl-phen-yl)diazen-2-ium-1-yl]naphthalen-2-olate.

The title zwitterion, C17H14N2O2, crystallizes with two independent mol-ecules in the asymmetric unit, both of which are approximately planar, the dihedral angles between the benzene ring and the naphthalene ring system being 4.39 (12)° in one mol-ecule and 5.83 (12)° in the other, and show an E conformation with respect to the azo double bond. An intra-molecular N-H⋯O hydrogen bond in each molecule helps to establish their near planar conformation. In the crystal, mol-ecules are linked through O-H⋯O hydrogen bonds into infinite chains running along the a-axis direction. In addition, the chains are stacked along the b axis via π-π inter-actions between the benzene and the naphthalene rings of adjacent mol-ecules, the centroid-centroid distances being 3.722 (3) and 3.823 (4) Å.

(E)-1-(2-Phenyl-diazen-2-ium-1-yl)naph-thalen-2-olate.

In the title zwitterionic compound, C16H12N2O, the dihedral angle between the phenyl ring and the naphthalene ring system is 17.85 (8)°; an intra-molecular N-H⋯O hydrogen bond occurs. In the crystal, π-π stacking is observed between naphthalene ring systems of adjacent mol-ecules, the centroid-centroid distance being 3.6486 (11) Å.

1-(4-Hy-droxy-phen-yl)-2-(2-oxidonaphthalen-1-yl)diazen-1-ium methanol hemisolvate.

In the title compound, C16H12N2O2·0.5CH3OH, the H atom of the -OH group has been transfered to the N atom in the azo group, forming a zwitterion. Hence, there is an intra-molecular N-H⋯O, rather than an O-H⋯N, hydrogen bond in the mol-ecule. The mol-ecule is almost planar, the dihedral angle between the benzene ring and the mean plane of the naphthalene ring system being 4.51 (6)°. In the crystal, mol-ecules are linked to and bridged by O-H⋯O hydrogen bonds involving the methanol mol-ecule, which is located about a twofold rotation axis, and hence half-occupied, forming zigzag chains along [001]. Mol-ecules are also linked via C-H⋯π and π-π inter-actions, the latter involving adjacent benzene and naphthalene rings and having a centroid-centroid distance of 3.6616 (13) Å, forming a three-dimensional network.