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A New Formulation of the Lindemann Mechanism of Unimolecular Reactions
Author(s) -
Qian RenYuan
Publication year - 2003
Publication title -
chinese journal of chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.28
H-Index - 41
eISSN - 1614-7065
pISSN - 1001-604X
DOI - 10.1002/cjoc.20030211209
Subject(s) - chemistry , steady state (chemistry) , mechanism (biology) , reactive intermediate , connection (principal bundle) , thermodynamics , gas phase , reaction mechanism , statistical physics , chemical physics , computational chemistry , catalysis , quantum mechanics , physics , organic chemistry , structural engineering , engineering
A new formulation of the Lindemann mechanism of unimolecular reactions in gaseous phase is presented, without the use of steady state hypothesis. It is hereby shown that the nature of applicability of steady state hypothesis in the regime of high reactant gas pressure is different from that in the regime of low gas pressure. In the former case it is an equilibrium approximation, while in the latter case it is a highly reactive intermediate approximation in no connection with a steady state. Furthermore for the latter case it is shown that in the classical formulation of Lindemann mechanism the use of steady state hypothesis is an ad hoc assumption. A highly reactive intermediate in the sense that its concentration is very small during the whole course of reaction is a necessary condition for the applicability of very reactive intermediate approximation. When the two distinctive nature of the applicability of steady state hypothesis is mixed‐up, wrong or useless conclusion may be arrived at. The only possible case of realizing a true steady state in a complex reaction is pointed out.