Spin polarization, delocalization and the effect of nonplanarity in hyperfine coupling constants of perfluorinated alkyl radicals

Density functional calculations for the structure and magnetic parameters of the perfluorinated ethyl and n-propyl radicals are described. It is seen that fluorine substitution leads not only to nonplanarity at the radical center but to delocalization of spin density onto the [F.sup.alpha] atoms and to spin polarization effects that lead to anomalies.