Changing Mixed-valence State of Hexacobalt Cluster by Substituting Central Metal Ion and by Electrochemical Reduction —Different Mixed-valence States of [M{Co(prolinato)2}6]4+ (M = Ba2+ and La3+)

Abstract

Clusters, Ba{Co(prolinato)2}6 and La{Co(prolinato)2}6, which are bridged by prolinato ligands, were crystallized as [M{Co(prolinato)2}6](ClO4)4. The Ba{Co(pro)2}6 cluster has two CoIII and four CoII and the La{Co(pro)2}6 cluster has one CoIII and five CoII; i.e., the mixed-valence state of the cobalt cluster is different according to the oxidation number of the central ion. The both mixed-valence clusters change into divalent hexacobalt clusters by electrochemical reduction.