MICROWAVE SPECTRUM AND STRUCTURE OF THE $OC---SO_{2}$ COMPLEX

Author Institution: Molecular Physics Division, National Institute of Standards and TechnologyThe microwave spectrum of the $OC---SO_{2}$ complex was observed in a pulsed-beam Fourier transform microwave spectrometer and exhibits an a- and c-type rotational spectrum. In addition to the normal isotopic species, the $^{34}SO_{2}$ and $^{13}CO$ substituted isotopic species were studied in natural abundance. Spectral analysis yields the rotational constants for $OC---SO_{2}: A = 8869.377(3) MHz, B = 1495.699(1)$ MHz, and $C =$ 1332.206(1) MHz. Further work is in progress on the spectrum of the $C^{18} O$ isotopic form. Stark effect measurements for the normal isotopic species provide the dipole moment components $ \mu a = 0.321(1) D, \mu_{b} = 0 D$ and $\mu_{c} = 1.600(2) D.$ The structural analysis, assuming fixed monomer geometries, shows that the CO unit and the symmetry axis of $SO_{2}$ lie in the a,c-plane of the T-shaped complex and the oxygen atoms of $SO_{2}$ are located symmetrically perpendicular to the a,c-plane. The center of mass separation, $R_{cm}$ is 4.059(1) {\AA} and the C-S distance is 3.506 {\AA} with the carbon atom participating in the van der Waals bond. Further details concerning the spectral and structure analysis will be given. Comparisons with related complexes will be presented