Wasserlösliche disulfonierte aromatische Ketone — Photophsikalische und photochemische Eigenschaften

Abstract

Water Soluble Disulphonated Aromatic Ketones — Photophysical and Photochemical Properties By the sulphonation of benzophenone, xanthone, thioxanthone, acridone, and methylacridone the disulphonated derivatives BPS, XS, TXS, AcS and MAcS are produced. Their disodium salts are well soluble in water. The absorption and the emission spectral data of these ketones are similar to those of the respective parent compounds. The S 1 state of BPS alone is of n — π* type, in all the other cases it possesses mainly π — π* character. The S 1 states can serve as donors in electron transfer reactions with iodonium salts. The kinetic curves of flash photolysis of these ketones in water show two decay processes, which are attributed to the triplet state and the long living ketyl radical. The triplet absorption spectra of the disulphonated ketones are very close to those of the unsubstituted ketones, but the life times of the former are much higher. The T 1 are quenched through onium salts by electron transfer reactions. Acryl amide, too, acts as a quencher for the triplets.