Matrix EPR and QM study of a model aromatic thioether radical-cation

The electronic structure and EPR properties of the model aromatic benzyl phenyl thioether radical cation [Ph-S-CH2-Ph]+ have been assessed and compared to those of the aliphatic analogues. In the most stable conformation spin and charge are almost equally distributed between the sulfur atom and the adjacent phenyl ring. In correspondence of favourable conformations spin and charge transfer from the aryl to the benzyl ring is predicted to occur thus suggesting the possibility of solvent effects on the reactivity distribution. Contrariwise to the aliphatic analogues, the major reaction mode in the chlorofluorocarbon matrix above 77 K is the C-S bond splitting.