Electrochemical studies on the intel-metallic interaction in polynuclear complexes - Preparation, structure and electrochemical properties of terpyridine complexes

The syntheses, structures and electrochemistry of two Co (II) complexes [Co(II)(L1)2](ClO4)2· 4CH32+CN(1) and [Co(II)(L2)2](ClO4)2· H2O(2) prepared from ligands Ll(4′-phenyl-2,2′ : 6′,2″-terpyridine) and L2(4′-ferrocenyi-2,2′ : 6′,2″-terpyridine) are reported in this paper. The electrochemical investigation shows that the oxidation potential of ferrocene unit in 2 has a 0. 14 V positive-shift from that of ferrocenyl group in L2 for the introduction of Co2+and, in the meantime, that the redox potential of cobalt centre in complex 2 has a 0. 06 V negative-shift from that of cobalt centre in complex 1. This observation strongly suggests that in complex 2, there is an intermetallic interaction between Co(II) and Fe(II) conducted by the molecular fragment.