CROSSED-BEAM ROVIBRATIONAL ENERGY-TRANSFER FROM S-1 GLYOXAL .2. UNIFORM SCATTERING CHARACTERISTICS FROM THE INITIAL LEVEL-0(0), LEVEL-5(1), AND LEVEL-8(1)

Results are reported for an extension to higher initial states of crossed molecular beam inelastic scattering from (1)A(u) trans-glyoxal (CHOCHO) by He collisions with 95-meV (770-cm(-1)) center-of-mass collision energy. A laser pump prepares glyoxal in the initial level nu(5)' = 509 cm(-1) or nu(8)' = 735 cm(-1) with high rotational selectivity about the top axis; K' = 0 for nu(5)' and K' = 0-3 for vs'. A dispersed fluorescence probe detects the final states of rotationally and of rovibrationally inelastic scattering with resolution of Delta K transitions. Semiquantitative relative cross sections are obtained for the state-to-state scattering. The rovibrational channels show the same extreme selectivity that is observed for scattering from lower levels. Only a single quantum change in the lowest frequency mode, the CHO-CHO torsion nu(7)' = 233 cm(-1), may be securely assigned. Scattering to much closer vibrational levels is not competitive. The state-resolved inelastic scattering characteristics of the three levels 0(0), 5(1), and 8(1) are now seen to be identical to within experimental uncertainty. The similarity involves both the competition between the rotational and rovibrational scattering channels as seen in the relative cross sections and the distribution of cross sections for the various Delta K processes within these channels. The experimental results are in agreement with the three-dimensional quantal scattering predictions of Kroes, Rettschnick, and Clary.