Crystal Structure Of Tri­Aqua­(4-Cyano­Benzoato-Κ2 O,O′)(Nicotinamide-Κn 1)Zinc 4-Cyano­Benzoate

Abstract

In the title salt, [Zn(C8H4NO2)(C6H6N2O)(H2O)3](C8H4NO2), inter­molecular O—H⋯O hydrogen bonds link two of the coordinating water mol­ecules to two free 4-cyano­benzoate anions. N—H⋯O, O—H⋯O and C—H⋯O hydrogen bonds link the mol­ecular components, enclosing (12), (8) and (9) ring motifs and forming layers parallel to (001)., 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 R 2 2(12), R 3 3(8) and R 3 3(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.