MICROWAVE MEASUREMENTS OF A DEUTERIUM ISOTOPE EFFECT ON HALOGEN QUADRUPOLE COUPLING IN METHYL HALIDES

Abstract

The $J = 1 \leftarrow 0$ rottional transitions in $CH_{3}{^{79}} Br, \;CH_{3}^{81}Br,\; CD_{3}^{79}Br$ and $CD_{3}^{81}Br$ were measured by standard microwave techniques using a C-band wavequide Stark cell. Some transitions were also measured using a beam maser spectrometer. Analysis of the data indicates a reduction in Br quadrupole coupling strengths when the methyl group is deuterated. This is in agreement with previous work on methyl chloride. Possible vibrational effects will be discussed.""