Chemical actinometer with 2-hydroxy-4′-dimethylaminochalcone

Abstract

The quantum yield of photochemical conversion of 2-hydroxy-4′-dimethylaminochalcone into 4′-dimethylaminoflavylium ion is approximately 0.23 in tetrahydrofuran solution in the presence of 5 mM p-toluenesulphonic acid on irradiation with UV light. The quantum yield is essentially constant as a function of the reaction conditions, such as the reaction time, temperature, substrate concentration and light intensity, but the absorption spectra of the reactant and product are well separated. These features are favourable for use as a chemical actinometer.