Vibrational analysis of 2-adamantanone and its deuterated isotopomers

Abstract

The vibrational analysis of 2-adamantanone and the group of all possible mono- and two gem-dideuterated 2-adamantanone isotopomers (2-adamantanone-3-d 1, 2-adamantanone- endo-4-d 1, 2-adamantanone- exo-4-d 1, 2-adamantanone-5-d 1, 2-adamantanone-6-d 1, 2-adamantanone-4,4-d 2 and 2-adamantanone-6,6-d 2) is presented. The assignments for fundamentals are based on the characteristic group frequencies, i.e. comparison with adamantane, Raman depolarization ratios, isotopic frequency shifts and are supported by the normal coordinate calculations. The force field was obtained from the semiempirical AM1 calculations and the assumed transferability of the scaling factors for adamantane. The average error between the observed and calculated frequencies is 11 cm −1. The effects of the carbonyl group and deuterium substitutions on the adamantane-like normal modes were investigated in terms of the harmonic mode scrambling analysis.