Collect. Czech. Chem. Commun. 1990, 55, 21-31

A result of resonant energy exchange between reactants and their chemical surrounding: The isokinetic relationship

Wolfgang Linert

Institute of Inorganic Chemistry, Technical University of Vienna, A-1060 Vienna, Austria


Many homologous series of reactions exhibit a common point of intersection in the ln k versus 1/T plots. This can be taken as a profound basis for the appearance of the isokinetic relationship (IKR) defining a temperature where rate (or equilibrium) constants of the series show a minimum in selectivity. The theoretically derived relationship describing the IKR and yielding a correlation between the isokinetic temperature and the frequencies available in an ideal heat bath is examined for real systems. It is shown that the role of the solvent in chemical reactions that exhibit isokinetic relationship is not only due to chemical interactions but also to energy transfer between reactants and solvents and vice versa.