Kinetics and mechanistic study of manganese(II)-catalyzed cerium(IV) oxidation of thiamine hydrochloride in aqueous perchloric acid medium by stopped flow technique

摘要: The kinetics of the manganese(II)-catalyzed oxidation thiamine hydrochloride by cerium(IV) in aqueous perchloric acid medium at a constant ionic strength 1.10 mol dm−3 was studied spectrophotometrically 15, 25, 35, and 45 °C stopped flow technique. reaction between exhibits 1:3 stoichiometry. main products were identified spot test, IR, 1H NMR, GC–MS studies. is first order manganese(II) has less than unit hydrochloride. As concentration increases rate decreases. added product cerium(III) retards reaction. active catalyst oxidant species as [Mn(H2O)4]2+ [Ce(OH)]3+, respectively. A probable mechanism involving free radicals formation complex substrate proposed. constants, activation parameters, thermodynamic quantities are calculated discussed.