Kinetic analysis of complex chemical activation and unimolecular dissociation reactions using QRRK theory and the modified strong collision approximation

Document Type

Article

Publication Date

1-1-2000

Abstract

A method to predict temperature and pressure-dependent rate coefficients for complex bimolecular chemical activation and unimolecular dissociation reactions is described. A three-frequency version of QRRK theory is developed and collisional stabilization is estimated using the modified strong-collision approximation. The methodology permits analysis of reaction systems with an arbitrary degree of complexity in terms of the number of isomer or product channels. Specification of both high and low pressure limits is also provided. The chemically activated reaction of vinyl radical with molecular oxygen is used to demonstrate the approach. Subsequent dissociation of the stabilized vinyl peroxy radical is used to illustrate prediction of dissociation rate coefficients. These calculations confirm earlier results that the vinoxy + O channel is dominant under combustion conditions. The results are also consistent with RRKM results using the same input conditions. This approach provides a means to provide reasonably accurate predictions of the rate coefficients that are required in many detailed mechanisms. The major advantage is the ability to provide reasonable estimates of rate coefficients for many complex systems where detailed information about the transition states is not available. It is also shown that a simpler 1-frequency model appears adequate for high temperature conditions. © by Oldenbourg Wissenschaftsverlag, München.

Identifier

0000735678 (Scopus)

Publication Title

Zeitschrift Fur Physikalische Chemie

External Full Text Location

https://doi.org/10.1524/zpch.2000.214.11.1533

ISSN

09429352

First Page

1533

Last Page

1568

Issue

11

Volume

214

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