Accelerated Photodimerization of Stilbenes in Methanol and Water

Article abstract of DOI:10.1021/jo00264a016

Photodimerization of stilbenes 1a-f, especially that of 4- and 3-acetylstilbenes (1c and 1d, respectively), is more efficient when a hydroxylic solvent (methanol or water) is employed as the reaction medium than when a nonhydroxylic solvent (hexane, benzene, or acetonitrile) is employed.The stilbenes 1a-f are more strongly fluorescent in methanol than in benzene.It is proposed that this accelerated photodimerization in the hydroxylic solvent originates from formation of a fluorescent solute-solute aggregate.