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

Abstract

The syntheses and crystal structures of Cu(C10H8N2)(C9H7O2)(H2O) (1) and [Cu2(C10H8N2)2(C7H6NO2)3(C7H7NO2)]·Cl·3H2O (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) Å, b = 13.8799 (8) Å, c = 16.3225 (9) Å, α = 84.916 (3)°, β = 88.551 (3)°, γ = 67.877 (3)°, V = 2516.0 (2) Å3, 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) Å, b = 18.1441 (11) Å, c = 18.9671 (13) Å, V = 4648.1 (5) Å3, 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 [Cu2(C10H8N2)2(C7H6NO2)2(C7H7NO2)2]2+ cation, in which both apical Hpaba molecules are N‐bonded to their metal ions.