An Electron Spin Resonance Method for Monitoring the Progressive Replacement of Fluorine by Alkoxy Groups in Perfluorobenzophenone

The use of electron spin resonance (e.s.r.) to follow the course of a chemical reaction which does not involve paramagnetic intermediates is reported. The principle of the method is the conversion of the reaction product into a paramagnetic species which may be characterized by e.s.r. In the present example, photoconversion of ketones into radical anions is used to follow the successive displacement of fluorine from perfluorobenzophenone.