State-resolved thermalization of singlet and mixed singlet-triplet states of CH{sub 2}
- Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973-5000 (United States)
The role of mixed states in the collision-induced thermalization, intersystem crossing, and reactive loss of CH{sub 2} (a-tilde{sup 1}A{sub 1}) has been monitored using Doppler-resolved transient frequency modulation absorption spectroscopy. Singlet CH{sub 2} is produced in a hot initial distribution of translation and rotational energy states in the 308 nm photodissociation of ketene in a large excess of argon. Collisions with Ar and ketene cool the translational and rotational degrees of freedom, while depleting the total singlet CH{sub 2} population through reaction and intersystem crossing. Direct monitoring of the time-dependent populations of rotational levels containing mixed singlet and triplet character reveals a rapid interconversion between the two components, but no discernable difference between the kinetics of the pure singlet and mixed states at longer times.
- OSTI ID:
- 20864287
- Journal Information:
- Journal of Chemical Physics, Vol. 125, Issue 8; Other Information: DOI: 10.1063/1.2345364; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-9606
- Country of Publication:
- United States
- Language:
- English
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