Crystal structure of triaqua(4-cyanobenzoato-κ2O,O′)(nicotinamide-κN1)zinc 4-cyanobenzoate

Abstract

The asymmetric unit of the title salt, [Zn(C8H4NO2)(C6H6N2O)(H2O)3](C8H4NO2), contains one complex cation and one 4-cyanobenzoate (CNB) counter-anion. The ZnII atom in the cation is coordinated by one 4-cyanobenzoate ligand, one nicotinamide (NA) ligand and three water molecules, the CNB anion thereby coordinating in a bidentate O,O′-mode through the carboxylate group. The latter, together with one water O atom and the N atom of the NA ligand, form a distorted square-planar arrangement, while the considerably distorted octahedral coordination sphere of the ZnII atom is completed by the two O atoms of additional water molecules in the axial positions. The dihedral angles between the planar carboxylate groups and the adjacent benzene rings in the two anions are 10.25 (10) and 5.89 (14)°. Intermolecular O—H...O hydrogen bonds link two of the coordinating water molecules to two free CNB anions. In the crystal, further hydrogen-bonding interactions are present, namely N—H...O, O—H...O and C—H...O hydrogen bonds that link the molecular components, enclosing R22(12), R33(8) and R33(9) ring motifs and forming layers parallel to (001). π–π contacts between benzene rings [centroid-to-centroid distances = 3.791 (1) and 3.882 (1) Å] may further stabilize the crystal structure.

Keywords

• crystal structure
• zinc
• transition metal complexes
• benzoic acid nicotinamide