15min:

MAHIN AFSHARI, M. DEHGHANY, J. N. OLIAEE, N. MOAZZEN-AHMADI, Department of Physics and Astronomy, University of Calgary, Calgary, AB T2N 1N4, Canada; A. R. W. MCKELLAR, Steacie Institute for Molecular Sciences, National Research Council of Canada, Ottawa, ON K1A 0R6, Canada.

Spectra of the weakly-bound OCS-C₂H₂ and OCS-C₂D₂ complexes in the region of the OCS ₁ fundamental ( 2062 cm^-1) are observed in a pulsed supersonic slit jet expansion probed with a tunable diode laser. For each complex two bands are observed and assigned to the near parallel and the T-shape isomers. The ground state rotational and centrifugal distortion parameters were previousely determined from microwave studies. Analysis of the infrared spectra gives accurate band origins as well as rotational and centrifugal distortion parameters for the upper states. All four bands show a red shift with respect to the monomer band origin, with the T-shape isomers having about 5.4 cm^-1 larger shift than the corresponding near parallel isomers.