C4-ring ligand-transfer reactions: applications to cluster chemistry. Crystal structures of [Ru5C(CO)13(η-C4Ph4)] and [Ru6C(CO)15(η-C4Ph4)]

Abstract

Redox-mediated ligand-transfer reactions between the cationic complex [Pd(η-C₄Ph₄)(Me₂CO)₂]²⁺ and the dianionic clusters, [Ru₅C(CO)₁₄]^2– and [Ru₆C(CO)₁₆]^2– afforded [Ru₅C(CO)₁₃(η-C₄Ph₄)]1 and [Ru₆C(CO)₁₅(η-C₄Ph₄)]2, respectively. The new clusters 1 and 2 have been characterised by spectroscopic techniques in solution and in the solid-state by single-crystal X-ray diffraction. In 1 the ring is co-ordinated to a basal ruthenium atom of the square-pyramidal cluster framework, while in 2 the octahedral metal core of the parent complex has opened slightly through the elongation of one Ru–Ru bond. The reasons for this structureal change have been analysed using extended-Hückel molecular-orbital calculations.