New complexes derived from the interaction of dicarbonylchlororhodium(I) and tris(triphenylphosphine)chlororhodium(I) with cyclopropane, butadiene, and perfluorobutadiene

Abstract

The interaction of dicarbonylchlororhodium(I) dimer with cyclopropane produces a dimeric complex, [(C₃H₆CO)RhCl(CO)]₂, which involves rhodium(III) in a five-membered ketonic heterocycle together with bridging halogens. The bridge can be cleaved by aromatic amines or triphenylphosphine (L) to give either a monomeric complex, (C₃HC₆O)RhCIL₂, or the salt [(C₃H₆CO)Rh(CO)L₂]Cl, where the heterocyclic ring is retained.

Perfluorobutadiene and [RhCl(CO)₂]₂ give again a rhodium(III) complex, [(C₄F₆)Rh(CO)₂Cl]₂, with the metal atom in an unsaturated perfluoroheterocycle.

Perfluorobutadiene and tris(triphenylphosphine)chlororhodium(I) also give a complex with a diolefinic heterocycle formed through loss of two fluorine atoms and of constitution (C₄F₄)RhCl(PPh₃)₂. By contrast buta-1,3-diene gives a chelating diolefin complex of rhodium(I), (C₄H₆)RhCl(PPh₃)₂.

The complexes are characterised inter alia by i.r. and n.m.r. spectroscopy.