Activation of Nitrous Oxide by Dinuclear Ruthenium Complexes

The dinuclear Ru­(II) complexes (arene)­Ru­(μ-Cl)3RuCl­(C2H4)­(PCy3) (arene = p-cymene or 1,3,5-C6H3iPr3) react with N2O under mild conditions to give OPCy3 and the trinuclear complexes (arene)­Ru­(μ-Cl)3Ru­(μ-Cl)3Ru­(arene). The N-heterocyclic carbene complex (p-cymene)­Ru­(μ-Cl)3RuCl­(C2H4)­(IMes) (IMes = 1,3-dimesitylimidazol-2-ylidene), on the other hand, reacts with N2O to give a mixed-valence Ru­(II)/Ru­(III) complex with a chelating alkoxy ligand. Dinitrogen complexes were identified as intermediates in all reactions. At elevated temperature, the carbene complex (p-cymene)­Ru­(μ-Cl)3RuCl­(C2H4)­(IMes) is able to catalyze the oxidation of alcohols with N2O.