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State-resolved thermalization of singlet and mixed singlet-triplet states of CH2.

Authors :
Komissarov, Anatoly V.
Ao Lin
Sears, Trevor J.
Hall, Gregory E.
Source :
Journal of Chemical Physics; 8/28/2006, Vol. 125 Issue 8, p084308, 5p, 3 Graphs
Publication Year :
2006

Abstract

The role of mixed states in the collision-induced thermalization, intersystem crossing, and reactive loss of CH<subscript>2</subscript> (ã <superscript>1</superscript>A<subscript>1</subscript>) has been monitored using Doppler-resolved transient frequency modulation absorption spectroscopy. Singlet CH<subscript>2</subscript> 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<subscript>2</subscript> 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. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
00219606
Volume :
125
Issue :
8
Database :
Complementary Index
Journal :
Journal of Chemical Physics
Publication Type :
Academic Journal
Accession number :
22257186
Full Text :
https://doi.org/10.1063/1.2345364