THERMOLUMINESCENCE OF NUCLEIC ACID CONSTITUENTS IN SOLUTION AFTER U.V.-IRRADIATION

Abstract— The thermoluminescence of purines and pyrimidines has been studied in ethylene glycol (EG)/water (2:1) glass matrices after ultraviolet (u.v.) irradiation at 77°K. An investigation of the mechanism of thennoluminescence has been made for adenine. The thermoluminescence involved biphotonic ionisation and recombination. The thermoluminescence depended on the square of the excitation light intensity, and the observed lifetime of the second photonabsorbing intermediate was the same as the phosphorescence lifetime. The emission spectrum lay in the same wavelength region as the phosphorescence spectrum. It was possible to bleach the thennoluminescence with visible light.