FLUORESCENCE QUENCHING OF AROMATIC-MOLECULES BY INORGANIC ANIONS IN POLAR-SOLVENTS

Electron transfer processes occurring in the systems containing aromat ic accepters and inorganic anions or organic neutral donor quenchers h ave been compared. The possibility of formation of free radicals in th e systems containing inorganic anions has been discussed. Importance o f the heavy atom effect depends on the spin-orbit coupling parameters of the formed radicals and on the rate constants of the back electron transfer from the radical pair to the molecular triplet state. The rat e constant of complexation of the primary radical pair by excess of in organic anions, which has been found to be a decisive step in formatio n of free radicals, is strongly dependent on solvent polarity.