FLUORESCENCE QUENCHING STUDY OF EuII-CROWN ETHER COMPLEXES BY 5-SUBSTITUTED-1,3-DIMETHYLURACILS

Abstract Fluorescence of EuII-crown ether complexes was quenched by 5-substituted-1,3-dimethyluracils. The quenching rate constant increased with increasing the electron-withdrawing properties of the substituents which supports the electron-transfer mechanism proposed for the EuIII/EuII photoredox system. A cavity size of the crown ether also influenced the quenching process.