Exciplex formation and electron-transfer in the photoreaction of 9,10-dicyanoanthracene and methyl 1,2-diphenylcyclopropene-3-carboxylate

Abstract

The title compounds form an emitting exciplex in benzene, which leads to the cycloadduct (3), whereas in polar solvents the isomeric adduct (4) and the dimer of the olefin are formed via an electron-transfer reaction which partially leads to triplet formation; the efficiency of the dimerization via the latter process is strongly enhanced in the presence of tetracyanobenzene.