CHEMICAL ACTINOMETER WITH 2-HYDROXY-4'-DIMETHYLAMINOCHALCONE

The quantum yield of photochemical conversion of 2-hydroxy-4'-dimethyl aminochalcone into 4'-dimethylaminoflavylium ion is approximately 0.23 in tetrahydrofuran solution in the presence of 5 mM p-toluenesulphoni c acid on irradiation with UV light. The quantum yield is essentially constant as a function of the reaction conditions, such as the reactio n 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. (C) 1997 Elsevier Science S.A.