PHOTOCHEMISTRY AND USE OF DECAHYDROACRIDINE-1,8-DIONES AS PHOTOSENSITIZERS FOR ONIUM SALT DECOMPOSITION

The photophysical and photochemical processes of the excited states of 3,3',6,6'-tetramethyl-1,2,3,4,5,6,7,8,9,10-decahydroacridine-1,8-diones are determined by the deactivation via (n-pi) and (pi-pi) triplet states. Therefore, solvents strongly affect the data of both the excited singlet and the triplet state. These states are well suited for transfer reactions to several energy or electron acceptors. Using onium salts as electron acceptors, the single-electron transfer processes exhibit a high barrier for the solvent reorganization energy, which cannot be compensated for by solvation or coulombic energies. Therefore, the rate constants and, consequently, the quantum yields of such photo-induced reactions are decreased in polar protic solvents compared with the values in non-polar media. Generally, the sensitized decomposition of aryl diazonium and diaryl iodonium salts by the decahydroacridine-1,8-diones is very efficient.