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(C 10 H 8 N 2 )(C 9 H 7 O 2 )(H 2 O) ( 1 ) and [Cu 2 (C 10 H 8 N 2 ) 2 (C 7 H 6 NO 2 ) 3 (C 7 H 7 NO 2 )] · Cl · 3H 2 O ( 2 ) are described [C 10 H 8 N 2 = 2,2′‐bipyridine (bipy), C 9 H 7 O 2 – = cinnamate anion (cinn – ), C 7 H 6 NO 2 – = p ‐amino benzoate anion (paba – ), and C 7 H 7 NO 2 = p ‐amino benzoic acid (Hpaba)]. Complex 1 [triclinic, space group P 1 (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) Å 3 , Z = 4] contains two molecules in the asymmetric unit: both feature a distorted square‐pyramidal CuN 2 O 3 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 P 2 1 2 1 2 1 (no. 19), a = 13.5061 (10) Å, b = 18.1441 (11) Å, c = 18.9671 (13) Å, V = 4648.1 (5) Å 3 , Z = 4] is dimeric with square pyramidal CuN 2 O 3 and CuN 3 O 2 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 (C 10 H 8 N 2 ) 2 (C 7 H 6 NO 2 ) 2 (C 7 H 7 NO 2 ) 2 ] 2+ cation, in which both apical Hpaba molecules are N‐bonded to their metal ions.