Conversions of ruthenium(III) alkyl complexes to ruthenium(II) through Ru-Calkyl bond homolysis

Single-electron oxidation of the Ru(II) complexes TpRu(L)(L')(R) (L = CO, L' = NCMe, and R = CH3 or CH2CH2Ph; L = L' = PMe3 and R = CH3) with AgOTf leads to alkyl elimination reactions that produce TpRu(L)(L')(OTf) and organic products that likely result from Ru-C-alkyl bond homolysis. Density functional calculations on TpRu(CO)(NCMe)(Me) and its Ru(III) cation indicate that the Ru-CH3 homolytic bond dissociation enthalpy is substantially reduced (48.6 to 23.2 kcal/mol) upon oxidation.