Spectral, kinetics, and redox studies on the transients formed on pulse radiolysis of aqueous solution of (4-methylthiophenyl)methanol

Article abstract of DOI:10.1246/bcsj.74.1649

Pulse radiolysis technique has been employed to investigate the nature and the redox properties of the transient species generated on radiolysis of aqueous solution of (4-methylthiophenyl)methanol (MTPM). Pulse radiolysis in 1,2-dichloroethane, reaction with specific one-electron oxidants (Cl₂^-, SO₄^-, Tl²⁺, Br) and reaction of OH radicals in acidic solution showed absorption bands at 320 and 545 nm; these are assigned to solute radical cation with positive charge on the benzene ring. OH-adduct was observed in neutral solution. The oxidation potential for MTPM/MTPM⁺ couple is determined to be 1.55 ± 0.04 V vs NHE. e_aq^- reacts with a bimolecular rate constant of 1.5 × 10⁹ dm³ mol^-1 s^-1 and the transient absorption bands (λax = 320, 470 nm) are assigned to the solute radical anion. E⁰ value for MTPM/MTPM^- couple is determined to be -1.84 ± 0.04 V vs NHE. The redox properties of the transient species formed on reaction with OH, H, and O^- have been evaluated.