PHOTODECHLORINATION OF MONOCHLOROBENZENES AND POLYCHLOROBENZENES BY REDUCTIVE PHOTOSENSITIZATION

Redox photosensitization was used to reduce mono and polychlorobenzenes with the electron-donor photosensitizers N,N,N',N'-tetramethyl-p-phenylenediamine (NTMP), N,N,N',N'-tetramethylbenzidine (NTMB), 3-dimethylaminophenol (NDMP) and 2-methoxyphenol (MEOP). The excited state energies of the photosensitizers and the redox potentials of the donor-acceptor couples show that the reductive electron transfer from the excited photosensitizers to the substrates is thermodynamically feasible. The results show that an electron-donor photosensitizer may increase the rate of dehalogenation of haloaromatic residues in the environment.