Showing papers by "Brian J. Orr published in 1987"

Coriolis‐assisted vibrational energy transfer in D2CO/D2CO and HDCO/HDCO collisions: Experiment and theory

Abstract: The technique of time‐resolved infrared–ultraviolet double resonance is used to characterize the rates and propensity rules for mode‐to‐mode vibrational (V–V) energy transfer in D2CO/D2CO and HDCO/HDCO collisions. Such processes are found to be exceptionally efficient when collision‐induced transfer is between the ν6 and ν4 modes of D2CO or between the ν5 and ν6 modes of HDCO: in the case of D2CO prepared in a specific ν6 rovibrational state by the 10R32 line of a CO2 laser, the rate of V–V transfer to specific states of the ν4 rovibrational manifold is approximately three times greater than the hard‐sphere gas‐kinetic collisional rate. This efficiency is much higher than for typical V–V transfer processes and approaches that of pure rotational relaxation, with the result that rotationally specific V–V transfer channels can be identified. The essential mechanism depends on the strong Coriolis coupling between the modes of D2CO or HDCO involved, as demonstrated by a semiclassical theoretical treatment whic...