Tetrakis(mu-4-methylbenzoato-kappa O-2:O ')bis[(isonicotinamide-kappa N)copper(II)]

Abstract

In the title centrosymmetric binuclear complex, [Cu-2(C8H7O2)(4)(C6H6N2O)(2)], the Cu atoms [Cu center dot center dot center dot Cu = 2.6375 (6) angstrom] are bridged by four 4-methylbenzoate (PMB) ligands. The four nearest O atoms around each Cu-II ion form a distorted square-planar arrangement, and the distorted square-pyramidal coordination is completed by the pyridine N atom of the isonicotinamide (INA) ligand. Each Cu-II ion is displaced by 0.2633 (1) angstrom from the plane of the four O atoms, with an average Cu-O distance of 1.974 (2) angstrom. The dihedral angles between carboxylate groups and the adjacent benzene rings are 7.88 (19) and 9.68 (10)degrees, while the benzene rings are oriented at a dihedral angle of 85.90 (9)degrees. The pyridine ring is oriented at dihedral angles of 8.59 (7) and 83.89 (9)degrees with respect to the benzene rings. In the crystal structure, intermolecular N-H center dot center dot center dot O hydrogen bonds link the molecules into a three-dimensional network. pi-pi contacts between the benzene rings and between the pyridine and benzene rings, [centroid-centroid distances = 3.563 (2) and 3.484 (2) angstrom, respectively] may further stabilize the crystal structure.