MICROWAVE MEASUREMENTS OF COBALT AND NITROGEN QUADRUPOLE COUPLING IN CO(CO)3NO

J = 2 --> 3, 3 --> 4, 4 --> 5, and 5 --> 6 transtions in the oblate symmetric top molecule cobalt tricarbonyl nitrosyl were measured using a Flygare-Balle type pulsed beam microwave spectrometer. K = 0 and K = 3 transitions were observed for J = 3 --> 4 and 4 --> 5. Hyperfine structure due to Co-59 and N-14 nuclear quadrupole coupling interactions was well resolved. The measured quadrupole coupling strengths are eQq(cc) (Co-59) = 35.14(30) MHz and eQq(cc) (N-14) = -1.59(10). Measured rotation and distortion constants are B0 = 1042.1590(4) MHz and D(j) = 0.17(8) kHz. The measured B value is 4% smaller than the B value calculated from electron diffraction data. Spin-rotation and a quadrupole distortion term were also obtained for Co-59.