1. Rotational energy transfer in D2CO (v4=1): IR–UV double resonance studies ofJ‐changing collisions
- Author
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R. G. Hynes, J. G. Haub, C. P. Bewick, Brian J. Orr, and J. F. Martins
- Subjects
Range (particle radiation) ,Chemistry ,Relaxation (NMR) ,General Physics and Astronomy ,Rotational–vibrational spectroscopy ,Physical and Theoretical Chemistry ,Atomic physics ,Spectroscopy ,Kinetic energy ,Ground state ,Resonance (particle physics) ,Rotational energy - Abstract
The technique of time‐resolved infrared–ultraviolet double resonance (IRUVDR) spectroscopy is used to characterize the rate and mechanism of state‐to‐state rotational energy transfer (RET) in D2CO/D2CO collisions. The investigations employ CO2‐laser irradiation to prepare a D2CO molecule in the v4=1, (J,Ka) =(18,11) rovibrational level of its X 1A1 electronic ground state. Vapor‐phase collisions with other D2CO (v=0) molecules then induce RET, with IRUVDR‐monitored quantum‐number changes ΔJ for the state‐selected molecule ranging between +3 and −7. Kinetic modeling of the resulting experimental data shows that the inelastic cross sections for such J‐changing rotational relaxation can be described adequately by simple scaling laws based on the rotational energy change ‖ΔE‖ for the state‐selected molecule, with a power‐gap fitting law proving marginally superior to an exponential‐gap fitting law. The range of ‖ΔJ‖ monitored in these experiments is sufficiently extensive to discredit a simple propensity‐rul...
- Published
- 1988
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