Electron spin resonance study of free radicals thermally generated from isatogen derivatives

Abstract

Free radicals obtained from a number of substituted isatogens dissolved in hydrocarbons and in alkaline media are analysed by e.s.r. spectroscopy. It is shown that these radicals originate by abstraction of a hydrogen atom from the solvent: a mechanism of formation is suggested and the structures assigned. In hydrocarbons the radicals have a long life and exhibit an enolic structure, while in alkaline media the ketonic form seems more likely. No evidence was found for “keto–enol” equilibrium in either media.