Relation between molecular and chemical dynamics for elementary radical reactions in viscous media

Excperimental data on the effect of viscosity on the kinetics of elementary chernical reactions of free radicals in solid matrices and viscous solutions are analysed. The dynamic effects in EPR spectroscopy are used for the simultaneous investigation of molecular and chemical dynamics. The intramolecular transformations in free radicals and the spin exchange in biradicals are considered. It is shown that the rates of such intramolecular reactions are controlled by the molecular dynamics of the chemical cage. The bibliography includes 58 references.