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

Abstract

The synthesis of a novel redox-active bipyridinium dimer ligand, 1,4-bis(4′-pyridyl-1′-pyridinio)phthalazine (Bpyph) dichloride and its magnetic coordination assemblies [(Bpyph)Cu^IIFe^II(C₂O₄)₃]·6.5H₂O (1) and [(Bpyph)Co^II₂(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 Δ and Λ 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.