Measurement of absolute rate coefficients

The evaluation of absolute rate coefficients of elementary reactions (hereafter referred to only as rate coefficients) is one of the most important steps in the kinetic analysis. Comparison of such values with our general chemical knowledge of radical reactions serves first as a check on the kinetic analysis and second, if shown to be reliable, they may be used in the kinetic analysis of other systems. It is often possible and useful to evaluate the rate coefficients directly in oxidation reactions as well as in much more simplified systems where many of the competing steps have been eliminated. 

In most free radical processes, a rate coefficient of interest is measured relative to a second rate coefficient which hopefully has been accurately evaluated. Thus the rate coefficient for reactions of R02- are measured, in most cases, relative, directly or indirectly, to the bimolecular termination of R02-. Rate coefficients for reactions involving either alkoxy or 

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These basic concepts and techniques were further extended in the fifties and sixties by Russell and coworkers [8] to structure reactivity relationships for aromatic compounds, by Mayo et al. [9] to copolymerization of oxygen with many vinyl monomers, and by Ingold and Howard to extensive measurements of absolute rate coefficients for peroxy and alkoxy radicals [10]. During this same period, an active group in the Soviet Union including Emanuel et al. [11] examined many complex oxidation systems. 

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