Infrared and Raman spectroscopic studies on the H–D equilibrium isotope effect in the electron-transfer equilibrium of thianthrene and its radical cation

Abstract

Infrared and resonance Raman spectra of thianthrene (Th), perdeuteriated thianthrene ([²H₈]Th) and their radical cation perchlorates (Th^˙+ClO^–₄ and [²H₈]Th^˙+ClO^–₄, respectively) have been measured. Comparison of the frequency shifts caused by the perdeuteriation and the radical cation formation of thianthrene enables evaluation of the free energy change of 137 cal mol^–1 for the electron-exchange equilibrium Th +[²H₈]Th^˙+⇌ Th^˙++[²H₈]Th.