Abstract
An electrochemical study of several N,N-diethyldithiocarbamato (Et2dtc) complexes of Ru(II), Ru(III), and Ru(IV) was carried out. [(CO)Ru(dtc)2]2. Ru(dtc)3, and ClRu(dtc)3 were studied by dc, ac, and cyclic voltammetric techniques in the solvents acetonitrile, propylene carbonate, and methylene chloride. The results indicate that the bimetallic complexes α- and β-[Ru2(dtc)5]+ are not formed as primary electrochemical oxidation products of Ru(dtc)3 or reduction products of ClRu(dtc)3. The electrochemical oxidation product of Ru(dtc)3 in CH3CN is [(CH3CN)Ru(dtc)3]+, and the metal-containing reduction product of ClRu(dtc)3, which exists as [(CH3CN)Ru(dtc)3]+Cl- in CH3CN, is Ru(dtc)3. In propylene carbonate, ClRu(dtc)3 is undissociated and exhibits a one-electron oxidation (E1/2 = 0.97 V) and a two-electron reduction (E1/2 = -0.77 V) to Ru(dtc)3
-. [(CO)Ru(dtc)2]2 shows an irreversible one-electron oxidation with E1/2 = 0.86 V vs. SCE in CH2Cl2. The electrolysis products of these complexes are compared to chemical redox products and redox mechanisms are discussed. Various redox reactions of the mixed-valence complexes Ru2(dtc)5, Ru(dtc)5
+, ClRu(dtc)3, and Ru(dtc)3 have been examined. Oxidation and isomerization reactions of Ru(dtc)3 and α-[Ru2(dtc)5]+ using BF3 gas have been studied in detail, and reaction mechanisms are proposed. The 1NMR spectra of α- and β-[Ru2(Me2dtc)5]+ have been assigned by variable-temperature and ligand-exchange studies.