Microwave Spectrum of hexa-Deutero Dimethyl Selenide in the Ground and Excited Torsional States
The ground state rotational spectra of 80Se and 78Se species of the hexadeutero dimethyl selenide have been measured in the region from 5 to 40 GHz. In both the cases, rotational and centrifugal distortion constants have been determined by a least square fit to about thirty transition frequencies. For the (CD3)2 80Se molecule, fourteen rotational transitions in the excited torsional states ṽ = l1, and ṽ = l2 were also recorded, out of which nine appeared as well resolved triplets. The potential barrier parameter V3 and the angle a between one of the ‘top axes’ and the ‘b axis’ have been determined by a least square fit of the mean value of the observed splittings in the ṽ = l1 and l2 states. The methyl top moment of inertia Iα was kept fixed at 6.35 amu Å2 , which is half of the observed inertia defect in the molecule.