Nuclear Magnetic Resonance in Radicals and in Radical Reactions

The present review examines papers devoted to the application of NMR to the study of the electronic structure of radicals, their solvation by various solvents, and the kinetics of radical reactions. The characteristic features and experimental difficulties of the NMR of radicals in the solid and liquid phases are examined as are the possibility of obtaining data on the mechanism of the delocalisation of the unpaired electron over large distances in the radicals themselves and in their complexes with solvents. It is shown how relaxation methods involving measurement of T₁ and T₂ and the dynamic polarisation of the nuclei have given information on the correlation times characterising the intensity of molecular motions in a liquid, and the energetics of these motions. The theoretical basis of these methods is examined. The last section gives the theory of the use of NMR spectra to measure the rates of various fast reactions. The results of the study of the kinetics of electron transfer and radical substitutions taking place with zero activation energy are discussed. The bibliography contains 61 references.