In situ spectroscopic evidence for facile, carbon monoxide mediated, reversible cleavage of neutral heterobimetallic rhodium–ruthenium complexes into ionic mononuclear complexes

Abstract

In situ IR and NMR spectroscopic evidence is presented for facile and reversible cleavage of ligand-bridged metal-metal bond sin heterobimetallic Rh-Ru complexes of the type [(C₅R₅)Ru(µ-CO)₂(µ-LL)RhX₂][R = H, LL = Ph₂PCH₂(dppm), Me₂PCH₂Pme₂(dmpm) or Ph₂PC(CH₂PPh₂(dppee); X = Cl, I] upon reaction with carbon monoxide under mild conditions to form [Ru(C₅R₅)(CO)₂(η¹-LL)]⁺ and [RhX₂(CO)₂]^–; an intermediate species in the cleavage process, [C₅H₅)(CO)₂Ru(µ-Me₂PCH₂PMe₂) Rh(CO)Cl₂], is detected by NMR spectroscopy.