title: Study of the P(4)O(7), P(4)O(6)S, and P(4)O(6)Se Vibrational Spectra.
abstract: The theoretical vibrational spectra of P(4)O(6)X (X = O, S, and Se) molecules are determined by employing the Hartree-Fock method in combination with a basis set of double-zeta quality plus polarization functions. A comparison of the three spectra is undertaken, and the shifts of the vibrational frequencies found in the spectra are analyzed. Two effects are considered to explain the changes in the band positions: the mass effect due to the replacement of oxygen by sulfur and selenium, respectively, and the bond strength effect. The mass effect of the substituent is as important as the different bond strengths of the P(V)=X bonds. Previous assignments of the bands in the P(4)O(7) spectrum are also corrected by the theoretical research, and a new correlation among the experimental vibrational spectra of the three compounds is put forth. Newly performed Raman polarization measurements confirm our theoretical findings.
authors.affiliation: Institute of Inorganic Chemistry, Bonn University, Gerhard-Domagk-Strasse 1, D-53121 Bonn, Germany.
authors.forename: A. R. S.
authors.initials: AR
authors.lastname: Valentim
authors.forename: B.
authors.initials: B
authors.lastname: Engels
authors.forename: S.
authors.initials: S
authors.lastname: Peyerimhoff
authors.forename: J.
authors.initials: J
authors.lastname: Clade
authors.forename: M.
authors.initials: M
authors.lastname: Jansen