Direct observation of non-RRKM behavior in femtosecond photophysically activated reactions

I-Ren Lee, Wei Kan Chen, Yu Chieh Chung, Po Yuan Cheng

Research output: Contribution to journalArticle

20 Citations (Scopus)

Abstract

A nonstatistical behavior has been observed in the photodissociation of two acyl cyanide compounds, R-C(O)-CN, where R = methyl and tert-butyl groups. The initial activation was achieved by femtosecond two-photon excitation followed by ultrafast internal conversion.The excited-state dissociation dynamics was followed in real time by monitoring the temporal evolution of CN (X) products. The observed product appearance time constants are in picosecond time scales and are markedly similar for the two compounds studied. Our analyzes revealed that the excited-state dissociation rate does not decrease with molecular size as much as statistical rate theory predicts, suggesting a nonergodic system in which the available vibrational energy does not redistributed statistically among all modes before the bond breakage occurs.

Original languageEnglish
Pages (from-to)10595-10599
Number of pages5
JournalJournal of Physical Chemistry A
Volume104
Issue number46
DOIs
Publication statusPublished - 2000 Nov 1

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Excited states
Observation
Photodissociation
Cyanides
dissociation
excitation
Photons
Chemical activation
internal conversion
cyanides
products
photodissociation
time constant
Monitoring
activation
photons
energy

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry

Cite this

Direct observation of non-RRKM behavior in femtosecond photophysically activated reactions. / Lee, I-Ren; Chen, Wei Kan; Chung, Yu Chieh; Cheng, Po Yuan.

In: Journal of Physical Chemistry A, Vol. 104, No. 46, 01.11.2000, p. 10595-10599.

Research output: Contribution to journalArticle

Lee, I-Ren ; Chen, Wei Kan ; Chung, Yu Chieh ; Cheng, Po Yuan. / Direct observation of non-RRKM behavior in femtosecond photophysically activated reactions. In: Journal of Physical Chemistry A. 2000 ; Vol. 104, No. 46. pp. 10595-10599.
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