Photochemical Reactions of Bromoanthracenes with N,N-Dimethylaniline in Solution

Both excimers and exciplexes have attracted the attention of molecular physicists and photochemists over the last decade. Owing to the use of laser photolysis, measurements of short-lived photocurrents, and pulse spectrofluorimetry, it became possible to satisfactorily explain photophysical processes occurring in molecular systems [1]. Excimers and exciplexes provide important steps of many photochemical reactions. Photochemical reactions of a variety of aromatic hydrocarbons have been shown to be preceded by excimer formation [2, 3]. The exciplxes, first detected in systems comprising aromatic hydrocarbons and tertiary aromatic amines [4], have frequently been observed in many classes of organic compounds. In articles [5, 6], numerous examples of photochemical reactions are reported for which exciplexes have been shown or postulated to provide intermediate steps. The exciplexes of anthracene with tertiary amines, which were carefully studied, proved to be photochemically active. The products and/or kinetics of these reactions were studied by Yang and coworkers [7], Saltiel, and co-workers [8] and Pac and Sakurai [9]. One of us (T. L.) together with his co-workers, studied the products and kinetics of a variety of photochemical reactions between N,N-dimethylaniline (DMA) and bromobenzene [10] as well as between DMA or other tertiary aromatic amines and chlorinated methanes [11]. The results of these studies, as well as those by Tasa, Pac, and Sakurai [12], revealed that exciplexes provided initial steps