Solvent-dependent quenching of the lowest excited singlet state of 9,10-dichloroanthracene by ground-state 2,5-dimethylhexa-2,4-diene yielding 9-chloroanthracene in acetonitrile or the [4+2]adduct in n-Heptane

Article abstract of DOI:10.1246/cl.1997.223

In acetonitrile, an exciplex formed between the lowest excited singlet state (¹DCA*) of 9,10-dichloroanthracene (DCA) and ground-state 2,5-dimethylhexa-2,4-diene (DMHD) generates the DCA radical anion as an intermediate for dechlorination of DCA yielding 9-chloroanthracene. In n-heptane, however, quenching of ¹DCA* by DMHD forms no exciplex and a dibenzobicyclo[2.2.2]octadiene-type compound (the [4+2] adduct) is obtained as the final product.