An examination of the reliability of methods of analyzing the experimental data from exchange reactions of molecules with nonequivalent hydrogen atoms

Abstract

Abstract Methods of analyzing the data from catalytic exchange reactions of molecules in which different groups of hydrogen atoms exchange at different rates have been tested using computer-generated isotopic distributions. The method of determining rates of exchange from such reactions at constant temperature, proposed by Harper, Siegel, and Kemball, is found to be satisfactory provided that the ratio of the rate constants for two groups of exchangeable hydrogen atoms is greater than about 5. On the other hand, the derivation of rate constants and Arrhenius parameters from data obtained by temperature-programmed experiments can only be considered reliable when the ratio of rate constants for the different groups of atoms is greater than about 20.