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

[(SO3)Co(cyclam)(NCS)] and [(SO3)Co(cyclam)-NCS-Ru(NH3)(4)(NCS)](BF4) complexes were synthesized and characterized by means nix-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 SO32- 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 x 10(6) is suggested for the mixed-valence complex based on the electrochemical and UV-Vis-NIR results. (C) 2011 Elsevier Ltd. All rights reserved.