The electrodeless discharge lamp:: a prospective tool for photochemistry -: Part 2.: Scope and limitation

We have previously reported results from the study of an original photochemical reactor consisting of an electrodeless discharge lamp (MWL) placed into the reactor vessel of a microwave oven [P. Klan, J. Literak, M. Hajek, J. Photochem. Photobiol. A: Chemistry 128 (1999) 145]. The microwave field generates ultraviolet irradiation in the lamp at the same time as it interacts with the studied sample, which is therefore affected by a simultaneous UV/VIS and MW irradiation. Here, five different common photoreactions have been investigated in the reactor: Norrish type II reaction of valerophenone and its p-methyl derivative, photo-Fries reaction, photoreduction of acetophenone, photolysis of a phenacyl ester, and a radical nucleophilic substitution of chlorobenzene in methanol. The reaction conversions and product distributions have been studied in terms of the MWL quality and the scale of the experiment. In addition, MW experiments were compared to those using a conventional UV lamp. The electrodeless lamp is presented as a very simple, economic, and efficient tool for photochemistry. (C) 2000 Elsevier Science B.V. All rights reserved.