Interactions between cis-ethylene ligands studied by inelastic neutron scattering

Abstract

The inelastic neutron scattering spectra of π-C₅H₅Rh(C₂H₄)₂, π-C₅H₅Rh(C₂H₄)SO₂ and [Rh-(C₂H₄)₂Cl]₂ have been measured and the torsional vibrations of their ethylene groups have been assigned. In the diethylene compounds in-phase and out-of-phase torsions have been observed and for [Rh(C₂H₄)₂Cl]₂ their frequencies are 112 ± 5 and 226 ± 5 cm^–1. A model has been proposed for the interaction between the ethylene groups and the experimentally observed frequencies have been expressed in terms of constants derived from this model.