M. REZAEI, J. NOROOZ OLIAEE, N. MOAZZEN-AHMADI, Department of Physics and Astronomy, University of Calgary, 2500 University Dr., N.W., Calgary, Alberta T2N 1N4, Canada; A. R. W. MCKELLAR, National Research Council of Canada, Ottawa, Ontario, K1A 0R6, Canada.
Infrared spectra of carbon disulphide clusters are studied in the region of the CS2 3 fundamental band ( 1535 cm-1), using a tuneable diode laser to probe a pulsed supersonic slit jet expansion. A symmetric rotor parallel band at 1551.438 cm-1 is assigned to CS2 tetramer. The likely structure is a staggered and tilted barrel with D2d symmetry, similar to the previously observed oblate tetramer of nitrous oxide, in reasonable agreement with that calculated from an empirical CS2 intermolecular potential function. This is the first high-resolution spectroscopic detection of CS2 tetramer, and the calculations suggest that there could be other lower energy isomers of (CS2)4 which are not yet observed.