Abstract
The principal concepts and methods whereby the pre-exponential factors for unimolecular gas-phase reactions may be found have been examined. The methods are based on the transition state theory which accounts successfully for all experimental data. The reactions have been classified taking into account the typical structure of the activated complex. The question of the effect of molecular structure on the value of the pre-exponential factor has been examined for each group of reactions. The general postulates have been illustrated by examples. The data employed embrace about 800 reactions.
The bibliography includes 177 references.