Cross conjugated free radicals. 2. The 2-pentafluorophenylallyl radical. An ESR and CNDO/INDO study

The ESR spectrum of the 2-pentafluorophenylallyl radical in solution is reported. It shows splittings from the fluorine substituents in addition to the usual allyl hyperfine splittings. Extensive CNDO/INDO calculations indicate that at the equilibrium geometry the allyl and phenyl planes are twisted by about 65°, and further allow an interpretation of the unusual fluorine Isotropic coupling constants in terms of π- as well as of σ-electron mechanisms. © 1979 American Chemical Society.