Electron Spin Resonance of the Thioxanthone S,Shyphen;Dioxide Mononegative Ion. Conjugation in Sulfones

摘要

The electron spin resonance spectrum of the thioxanthone S,Shyphen;dioxide mononegative ion is investigated. Proton hyperfine splittings are reported. Moffitt's treatment of the expansion of theMhyphen;shell octet in sulfur is employed in the calculation of spin densities and the occurrence of sulfone conjugation in this radical is confirmed. Unpaired spin densities, calculated using onehyphen;electron MO theory with variation of Coulomb and resonance integral parameters, are not in close agreement with experiment. The McLachlan SCF theory with variation of parameters is applied.Negativespin densities are predicted at the 2,4 positions and good agreement with the hyperfine spectrum is obtained for reported ranges of the MO parameters.