The Mechanism of Homogeneous Organic Reactions from the, Physical-Chemical Standpoint

Abstract

IN recent years much attention has been given to the study of heterogeneous catalysis, and great advances have been made in our knowledge of the influence of surfaces in promoting chemical change. Prof. Rice's present work provides a welcome reminder of the importance of the complementary problem of homogeneous catalysis, since, as he points out in his introduction, organic compounds are often non-reactive when freed from catalysts, but undergo rapid change when the necessary catalyst is supplied. As illustrations of this non-reactivity he cites the case of ethylene and bromine, which “practically cease to react when dry and enclosed by ‘non-polar’ walls of paraffin wax,” and the analogous phenomena whereby “the conversion of nitrocamphor to the pseudo form and the tautomerism of keto-enol isomers” are arrested when these substances are “free from catalysts and enclosed in a vessel with non-polar walls.” A few exceptional cases, such as the racemisation of pinene and the thermal decomposition of acetone, in which chemical changes appear to take place in the vapour phase at elevated temperatures in the absence of a catalyst, are, however, described in the final paragraph of the book. In general, therefore, it is admitted that organic reactions, which normally proceed only under the influence of a catalyst, may also take place in the absence of a catalyst when collisions of exceptional violence occur.

The Mechanism of Homogeneous Organic Reactions from the, Physical-Chemical Standpoint.

By Prof. F. O. Rice. (American Chemical Society Monograph Series.) Pp. 217. (New York: The Chemical Catalog Co., Inc.; London: Arthur F. Bird, 1928.) 5 dollars.