Solid-state photolysis of anthracene-linked ammonium salts: The search fortopochemical anthracene photodimerizations

The reaction of 9-N,N-dimethylaminomethylanthracene 1 with aromatic carboxy lic acids gave crystalline salts (2a, 2b, 3a and 3b), which were irradiated in the solid state. Whereas salt 3a was selectively transformed to the dim er 4a, the other salts were photoinert. The results were rationalized on th e basis of X-ray structure analysis. In the presence of oxygen, solid-state irrradiation of anthracene salt 3b leads to selective photooxygenation. Th e selectivity of both solid-state photoreactions was not observed in soluti on. (C) 2000 Elsevier Science Ltd. All rights reserved.