Asymmetric heterobimetallic mixed-valence complex trans-[(SO3)Co(cyclam)(NCS)Ru(NH3)4(NCS)](BF4): Synthesis and characterization

Abstract: [(SO3)Co(cyclam)(NCS)] and [(SO3)Co(cyclam)-NCS-Ru(NH3)4(NCS)](BF4) complexes were synthesized and characterized by means of X-ray diffraction, electrochemistry, elemental analysis, and spectroscopic techniques. Crystallographic and FTIR data indicated NCS− ligand is coordinated to Co through the nitrogen atom in the monomer species. Electrochemistry and FTIR data of the material isolated after reductive electrolysis of [(SO3)Co(cyclam)(NCS)] hint that NCS− and SO3 2− are released thus forming [Co(cyclam)(L)2]2+, where L is solvent molecules. The formation of the heterobimetallic mixed-valence complex induced a thermodynamic stabilization of Co and Ru metal atoms in the oxidized and reduced states, respectively. According to the Robin and Day classification, a Class II system with a comproportionation constant of 5.78×106 is suggested for the mixed-valence complex based on the electrochemical and UV–Vis–NIR results. [Copyright &y& Elsevier]