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

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 (Cl-2(.-), SO4.-, Tr2+, Br-.) and reaction of (OH)-O-. 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 x 10(9) dm(3) mol(-1) s(-1) and the transient absorption bands (gimel (max) = 320, 470 nm) are assigned to the solute radical anion. E-0 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)-O-., H-., and O.- have been evaluated.