One- and two-dimensional coordination assemblies of a novel redox-active bipyridinium dimer ligand with magnetic oxalate complexes

The synthesis of a novel redox-active bipyridinium dimer ligand, 1,4-bis(4ʹ-pyridyl-1ʹ-pyridinio)phthalazine (Bpyph) dichloride and its magnetic coordination assemblies [(Bpyph)CuIIFeII(C2O4)3].6.5H2O (1) and [(Bpyph)CoII2(C2O4)3].5.5H2O (2) are described. X-Ray single-crystal diffraction studies confirm that compound 1 is built from [CuFe(C2O4)3]2- units bridged sequentially by Bpyph cations to form polymeric chains with (delta)and (lambda)enantiomers in [Fe(C2O4)3]4-. Compound 2 consists of honeycomb layers of the cobalt oxalate complex [Co2(C2O4)3]2- interleaved by Bpyph cations. The magnetic susceptibility data show antiferromagnetic interaction in both compounds with Weiss constants -2.38 K for 1 and -38 K for 2.