Reactions of µ3-oxo-triruthenium carboxylates with π-acid ligands

Abstract

The interactions of the oxo-centred ruthenium(III) acetate, [Ru₃O(CO₂Me)₆(MeOH)₃]CO₂Me or species formed from it by reduction, with carbon monoxide, methyl isocyanide, sulphur dioxide, and nitric oxide have been studied. Only a monocarbonyl, e.g., Ru₃O(CO₂Me)₆(CO)(py)₂ is formed and the six bridged carboxylate groups of the original oxo-centred species rearrange to give two bridged and four bidentate carboxylate groups. The complexes have been studied, where feasible, by i.r. and n.m.r. spectroscopy and their electrochemical behaviour investigated. The mean oxidation state for ruthenium of 2⅓(or II, II, III) in a trinuclear complex has been characterised. The complexes Ru(CO)(CO₂Me)₂(PPh₃)₂ and Ru(MeNC)₂(CO₂Me)₂(PPh₃)₂ are described; the former has one bidentate and one monodentate acetate and appears to be a non-rigid molecule. Bis- and tris-isocyanide complexes were obtained, with acetate and propionate respectively, and mononitrosyl and sulphur dioxide complexes were prepared.