Methylene blue sensitized oxidation of 2-imidazolidinethione in microheterogeneous medium

Abstract

The methylene blue (MB) sensitized photooxidation of 2-imidazolidinethione (IT) in sodium dodecylsulphate (SDS) aqueous micellar solution gives 2-imidazolidine-2-yl-sulphinic acid as the primary product. Higher quantum yields of product formation at high [SDS] are due to the increased efficiency of energy transfer/electron transfer processes in MB-³O₂/ MB-IT pairs respectively. The effect of various kinetic parameters establishes the reaction to proceed through the participation of singlet oxygen. The ionic mechanism is suggested at higher IT concentration. Salt effect supports the stabilization of polar transition state/formation of dye rich micellar aggregates.