Extended gorin model for radical-radical recombination reactions

Pitt, I.G., Gilbert, R.G. and Ryan, K.R. (1995) Extended gorin model for radical-radical recombination reactions. Journal of Physical Chemistry, 99 1: 239-247. doi:10.1021/j100001a037

Author Pitt, I.G.
Gilbert, R.G.
Ryan, K.R.
Title Extended gorin model for radical-radical recombination reactions
Journal name Journal of Physical Chemistry   Check publisher's open access policy
ISSN 0022-3654
Publication date 1995-01
Sub-type Article (original research)
DOI 10.1021/j100001a037
Volume 99
Issue 1
Start page 239
End page 247
Total pages 9
Place of publication Washington, DC, United States
Publisher American Chemical Society
Language eng
Formatted abstract
Radical-radical recombination reactions (e.g., CH 3 + CH 3 ⇄ C 2H 6) proceed with no barrier through simple-fission transition states. The application of transition state theory (TST) to these reactions is discussed, achieving a new understanding of the dividing surface and dynamical assumption implicit in all TST treatments of these reactions. A reinterpretation of the modified Gorin model for such transition states is discussed which removes several inconsistencies from this model and greatly improves data prediction and interpretation for radical-radical recombination reactions (and the reverse unimolecular dissociations) in the gas phase. The suggested model is an extension of the basic Gorin approach, which treats the transition state as consisting of two moieties which have the same vibrational and rotational properties as the fully separated fragments. The method discussed here proposes an improvement of the modified Gorin model Hamiltonian that better describes simple-fission reaction dynamics by completely excluding trajectories occurring with unfavorable orientations of the combining moieties from the transition state theory rate coefficient. This new approach is sufficiently simple that the description is applicable to any system and thus can be routinely implemented with modest computational resources. Comparison with experiment and with more precise theoretical descriptions for ethane and neopentane decomposition reactions shows that this treatment provides quantitative agreement for ethane. It is also concluded that more sophisticated treatments of transitional modes than afforded by hindered rotor models are needed for the description of transition states with bulky moieties at elevated temperatures, such as the neopentane decomposition system described here.
Keyword Transition-state theory
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Non-UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: School of Chemistry and Molecular Biosciences
Centre for Nutrition and Food Sciences Publications
Version Filter Type
Citation counts: TR Web of Science Citation Count  Cited 16 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 0 times in Scopus Article
Google Scholar Search Google Scholar
Created: Mon, 07 Mar 2011, 15:55:36 EST