THE GROUND-STATE VIBRATIONAL STRUCTURE OF SCCL2 - OBSERVATION OF BACKBONE IVR

Vibrationally excited SCCl2 is a model system for energy redistributio n among backbone vibrational modes. Over 200 transitions in the (X) ov er tilde <-- (B) over tilde dispersed fluorescence spectrum of thiopho sgene have been observed to map the ground electronic surface up to 15 000 cm(-1). An analytical six-dimensional potential surface derived fr om ab initio calculations has been fitted directly to about 100 of th e transitions to provide an experimentally derived surface for intramo lecular vibrational energy redistribution (IVR) quantum dynamics calcu lations. Higher resolution stimulated emission pumping spectra from di fferent vibrational levels in the (B) over tilde state reveal a comple x progression from unfragmented/slightly Fermi-resonant states, to hig hly fragmented states above nu(1) = 8. (C) 1998 Elsevier Science B.V. All rights reserved.