ChemInform Abstract: Rovibrational Energy Transfer from the (00, K′= 0) and (72, K′= 0) Levels of S1 Glyoxal in Crossed Beam Collisions with H2.

Abstract

Crossed molecular beams have been used to study rotationally and vibrationally inelastic scattering from the (72, K’=0) and the (00, K’=0) levels of 1Au (S1) trans‐glyoxal in collision with H2. The center‐of‐mass collision energy was approximately 80 meV (650 cm−1). Laser excitation was used to select each of the initial vibrational levels with rotational states limited to J’=0–10, K’=0. Dispersed fluorescence was used to monitor quantitatively the final rotational and vibrational levels populated in single collision scattering. Vibrationally inelastic scattering from each initial level has an absolute cross section large enough to allow the process to be observed easily with resolution of accompanying ΔK rotational state changes. Although many final vibrational levels are energetically accessible and in principle observable, only those reached by ±1 quantum changes in the lowest frequency mode, the OHC–CHO torsion ν7, are seen. From the initial level 72, the cross sections for Δυ7=+1 and Δυ7=−1 are nearl...