15min:

S. THORWIRTH, M. C. MCCARTHY, C. A. GOTTLIEB, P. THADDEUS, Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, U.S.A. and Division of Engineering and Applied Sciences, Harvard University, 29 Oxford Street, Cambridge, MA 02138, U.S.A.; H. GUPTA, J. F. STANTON, University of Texas at Austin, Department of Chemistry and Biochemistry, Institute for Theoretical Chemistry, Austin, TX 78712, U.S.A. .

The C_2v forms of thiozone, S₃, and tetrasulfur, S₄, have been investigated by Fourier transform microwave spectroscopy of a supersonic molecular beam. Both molecules represent the global minima on their respective potential energy surfaces. Besides the parent molecules the mono-³⁴S isotopomers have been investigated in natural abundance. For thiozone, a substantial number of vibrational satellites has been detected in addition. The analysis of the spectroscopic data will be discussed and a comparison to recent high-level quantum chemical calculations at the CCSD(T) level of theory will be given. From a calculation of the cubic force field the rotation-vibration interaction constants have been calculated and the mixed experimental-theoretical r_e structures have been obtained.