THE STRUCTURE OF CO-OCS - A SPECTROSCOPIC AND THEORETICAL INVESTIGATION

The spectrum of the weakly bound complex CO-OCS has been measured in t he infrared using direct absorption diode laser spectroscopy in a supe rsonic jet, and in the microwave region using a pulsed nozzle Fourier- transform instrument. In addition, microwave spectra of the two isotop omers (CO)-C-13-OCS and CO-(OCS)-S-34 were recorded. A T shaped struct ure has been determined with the carbon atom in CO closest to the OCS (RMS angle+/-20.5 degrees with respect to the intermolecular axis) and the sulphur end of OCS pointing away from CO (vibrationally averaged angle 105.7 degrees). The ground state centre of mass separation is 4. 17 Angstrom. The effective structure is rationalized by a simple poten tial incorporating a distributed multipole analysis of the electrostat ic charge distribution, distributed dispersion contribution and a cyli ndrical hard core repulsion, with discussion of the implications for t he potential of including correlation effects in the CO multipole.