VIBRATIONAL PREDISSOCIATION SPECTROSCOPY OF (CH3OD)2 AND (CH3OH)(CH3OD) IN THE 9.6-MU-M REGION

Vibrational predissociation spectra of isotopomers of methanol dimer have been recorded in the 9.6-μm region. Using the beam depletion method, we have observed vibrational transitions at 1028.29 and 1053.49 cm-1 for (CH3OD)2 with Lorentzian line widths of 2.83 and 1.18 cm-1, respectively. These transitions are blue-shifted from the fully protonated dimer by 1.88 and 1.30 cm-1, respectively. Spectra were also measured for the mixed dimer (CH3OH)(CH3OD). Analysis shows that there is a preference of the deuterated subunit to occupy the donor position in the mixed dimer. It is estimated that the population of dimer to monomer ratio is 1% under conditions where only the monomer and dimer are present in the molecular beam. © 1990 American Chemical Society.