Theoretical study of the ground state vibrations of methoxydifluorophosphine-d 0 and -d 3

Abstract

The results of ab initio SCFMO calculations using the 3-21G ∗, 4-31G ∗ and 6-31G ∗ basis sets for methoxydifluorophosphine-d 0, d 3 compounds are presented. The optimized geometries obtained from these calculations are compared with the experimental bond distances and bond angles obtained from a combined study of electron diffraction and rotational data. The vibrational spectra (frequencies and intensities) of the compound and the d 3-isotopomer were calculated using all three basis sets. The predicted spectra were compared with the experimental IR and Raman spectra of the molecule and those of the d 3-istopomer in the gas phase. The calculated potential energy distribution provides a basis for assigning the experimental spectra. The calculated isotopic frequency shifts for 2H substituted methoxydifluorophosphine were also found to be in close agreement with the experimental isotopic frequency shift. The calculated IR intensity pattern also shows good agreement with the experimental spectrum.