Computations of ESR coupling constants in organic radicals. I. General theory and applications to benzene and toluene

Abstract

We discuss the removal of spin contamination from an unrestricted Hartree-Fock wavefunction and we use the theoretical expressions to calculate the ESR coupling constants of the benzene and toluene radicals and radical anions. We investigate the Jahn-Teller distortion in the benzene radical anion and the rotational motion of the methyl group in the toluene radical anion in order to study their effects on the corresponding ESR spectra. We also present some general predictions regarding the spin and the energy derived from unrestricted Hartree-Fock computations.