MICROWAVE-SPECTRUM OF DIMETHYLSULFIDE - DETERMINATION OF THE METHYL TOP MOMENT OF INERTIA

The vibrational ground-state rotational transitions of the two-top molecule dimethylsulfide (CH3)2S show triplet or quartet structure due to the methyl top internal rotation. A sufficient number of quartets originating from near-degeneracies have been included in earlier data to obtain a reliable value of the methyl top moment of inertia, Iirα = 3.242 amu Å2. For a molecule of this type Iα can also be independently determined from a consideration of the carefully corrected inertial defect Δ. We then obtain Iaα = 3.134 amu Å2, which is of r0 quality and (employing Δ of both (CH3)2S and (CD3)2S) Ieα = 3.212 amu Å2, which should approach re quality. Copyright © 1980 by Academic Press, Inc.