Crystal structure, Hirshfeld surface analysis and geometry optimization of 2-hy-droxy-imino-N-[1-(pyrazin-2-yl)ethyl-idene]propano-hydrazide.

In the mol-ecule of the title compound, C9H11N5O2, the oxime and hydrazide groups are situated in a cis-position in relation to the C-C bond linking the two functional groups. The CH3C(=NOH)C(O)NH fragment deviates from planarity because of a twist between the oxime and amide groups. In the crystal, mol-ecules are linked by O-H⋯O hydrogen bonds, forming zigzag chains in the [013] and [03] directions.

Crystal structure of (2,2'-bi-pyridine-κ2N,N')bis-(3,5-di-tert-butyl-o-benzo-quinonato-κ2O,O')ruthenium(II).

In the title mononuclear complex, [Ru(C14H20O2)2(C10H8N2)], the RuII ion has a distorted octa-hedral coordination environment defined by two N atoms of the chelating 2,2'-bi-pyridine ligand and four O atoms from two 3,5-di-tert-butyl-o-benzo-quinone ligands. In the crystal, the complex mol-ecules are linked by inter-molecular C-H⋯O hydrogen bonds and π-π stacking inter-actions between the 2,2'-bi-pyridine ligands [centroid-centroid distance = 3.538 (3) Å], resulting in a layer structure extending parallel to the ab plane.

Crystal structure of 9,9'-{(1E,1'E)-[1,4-phenyl-enebis(aza-nylyl-idene)]bis-(methanylyl-idene)}bis-(2,3,6,7-tetra-hydro-1H,5H-pyrido[3,2,1-ij]quinolin-8-ol).

The whole mol-ecule of the title compound, C32H34N2O2, is generated by inversion symmetry; the central benzene ring being situated about the crystallographic inversion center. The aromatic ring of the julolidine moiety is inclined to the central benzene ring by 33.70 (12)°. There are two intra-molecular O-H⋯N hydrogen bonds in the mol-ecule, generating S(6) ring motifs. The conformation about the C=N bonds is E. The fused non-aromatic rings of the julolidine moiety adopt half-chair conformations. In the crystal, adjacent mol-ecules are linked by pairs of C-H⋯π inter-actions, forming a ladder-like structure propagating along the a-axis direction.

Crystal structure of 5-[(4-carb-oxy-benz-yl)-oxy]isophthalic acid.

The mol-ecular shape of the title compound, C16H12O7, is bent around the central CH2-O bond. The two benzene rings are almost perpendicular to one another, making a dihedral angle of 87.78 (7)°. In the crystal, each mol-ecule is linked to three others by three pairs of O-H⋯O hydrogen bonds, forming undulating sheets parallel to the bc plane and enclosing R 2 (2)(8) ring motifs. The sheets are linked by C-H⋯O hydrogen bonds and C-H⋯π inter-actions, forming a three-dimensional network.

Crystal structure of poly[di-aqua-(µ-2-carb-oxy-acetato-κ(3) O,O':O'')(2-carb-oxy-acetato-κO)di-µ-chlorido-dicobalt(II)].

The asymmetric unit of the title polymer, [Co2(C3H3O4)2Cl2(H2O)2] n , comprises one Co(II) atom, one water mol-ecule, one singly deprotonated malonic acid mol-ecule (HMal(-); systematic name 2-carb-oxy-acetate) and one Cl(-) anion. The Co(II) atom is octa-hedrally coordinated by the O atom of a water mol-ecule, by one terminally bound carboxyl-ate O atom of an HMal(-) anion and by two O atoms of a chelating HMal(-) anion, as well as by two Cl(-) anions. The Cl(-) anions bridge two Co(II) atoms, forming a centrosymmetric Co2Cl2 core. Each malonate ligand is involved in the formation of six-membered chelate rings involving one Co(II) atom of the dinuclear unit and at the same time is coordinating to another Co(II) atom of a neighbouring dinuclear unit in a bridging mode. The combination of chelating and bridging coordination modes leads to the formation of a two-dimensional coordination polymer extending parallel to (001). Within a layer, O-Hwater⋯Cl and O-Hwater⋯O hydrogen bonds are present. Adjacent layers are linked through O-H⋯O=C hydrogen bonds involving the carb-oxy-lic acid OH and carbonyl groups.