Electron spin resonance spectra of free radicals. Part 1. α-Fluoromethylbenzyl radical and related species

Abstract

The e.s.r. spectrum of the radical PhCHCH₂F has been studied for a variety of solvents and over a range of temperature. INDO calculations have been carried out for several conformations of the radical. The evidence suggests that rotation about the C–CH₂F bond is hindered, with one of the rotamers strongly destabilized by steric interaction between the fluorine atom and the phenyl group. E.s.r. spectra of a number of related radicals have also been studied. Rotation of CH₂F and CHF₂ substituents is hindered, and some of the radicals appear to be significantly non-planar at the radical centre.