Inelastic neutron scattering spectra of partially deuterated dimethylmethylphosphonates

Abstract

Incoherent inelastic neutron scattering spectra, recorded at several temperatures, are reported for CH₃PO(OCD₃)₂ and CD₃PO(OCH₃)₂. The spectra are interpreted with the aid of model calculations, using semi-empirical methyl torsion potentials. There are indications that two different CH₃-rotors are present in CD₃PO(OCH₃)₂. Barriers to internal rotation have been calculated from the spectra under the approximation of rigid threefold rotors. The results are discussed with reference to theoretical calculations on the normal compound.