The hyperfine coupling constants of some fluorinated free radicals

Abstract
The electron resonance spectra of some fluorobenzyl radicals and fluorobenzaldehyde radical anions are reported. The observed hyperfine coupling constants are discussed in terms of π-electron spin densities estimated from semi-empirical molecular orbital calculations. Only one isomer is observed in the spectrum of the o-fluorobenzaldehyde radical anion, whereas two isomers are observed in the meta compound.