[Molecular oxygen quenching of the singlet and triplet states of poryphyrins].

Rate constants of molecular oxygen quenching in solutions of singlet and triplet states of chlorophyll porphyrines molecules and their complexes with metals were measured with the help of the methods of laser photolysis, impulse fluorometry and luminescence. It has been shown that the quenching of fluorescence results from the intensification of intercombinational transition into the triplet state. The mechanism of quenching of the triplet state is discussed.