Group vibrations and the vibrational analysis of molecules containing methylene groups. Part II. Ethylene oxide, d4-ethylene oxide, and ethylene sulfide

Vibrational analyses, based on the group frequency factorization procedure of King and Crawford, are reported for ethylene oxide, d4-ethylene oxide, and ethylene sulfide in an attempt to decide between two possible vibrational assignments for these molecules.The results, whilst not providing an unequivocal decision between the assignments, nevertheless do suggest that the higher frequencies in the A2 and B2 species may be preferentially assigned to the methylene rocking modes.