Syntheses and Structures of Monomeric and Dimeric Ternary Complexes of Copper(II) with 2,2′-Bipyridyl and Carboxylate Ligands

The syntheses and crystal structures of Cu(C10H8N2) (C9H7O2)(H2O) (1) and [Cu-2(C10H8N2)(2)(C7H6NO2)(3)(C7H7NO2)]Cl3H(2)O (2) are described [C10H8N2 = 2,2'-bipyridine (bipy), C9H7O2 = cinnamate anion (cinn-), C7H6NO2- = p-amino benzoate anion (paba(-)), and C7H7NO2 = p-amino benzoic acid (Hpaba)]. Complex 1 [triclinic, space group P1 _ (no. 2), a = 12.0357 (7) , b = 13.8799 (8) angstrom, c = 16.3225 (9) angstrom, alpha = 84.916 (3)degrees, beta = 88.551 (3)degrees, gamma = 67.877 (3)degrees, V = 2516.0 (2) angstrom(3), Z = 4] contains two molecules in the asymmetric unit: both feature a distorted square- pyramidal CuN2O3 chromophore arising from the coordination of a bidentate bipy ligand, two monodentate cinn- anions, and a water molecule to the metal ion. The cation in complex 2 [orthorhombic, space group P212121 (no. 19), a = 13.5061 (10) angstrom, b = 18.1441 (11) angstrom, c = 18.9671 (13) angstrom, V = 4648.1 (5) angstrom(3), Z = 4] is dimeric with square pyramidal CuN2O3 and CuN3O2 metal coordination polyhedra: each metal ion is coordinated by a bidentate bipy ligand and two bridging paba- anions; the apical coordination site of one is occupied by an O- bonded paba- anion and the other by an N- bonded Hpaba neutral molecule. The cation in 2 is isomeric with the previously reported [Cu-2(C10H8N2)(2)(C7H6NO2)(2)(C7H7NO2)(2)](2+) cation, in which both apical Hpaba molecules are N- bonded to their metal ions.