Intense Dyes through Chromophore-Chromophore Interactions: Bi- and Trichromophoric Perylene-3,4:9,10-bis(dicarboximide)s

Simple perylene dyes, which are known for their high extinction coefficients, are converted into intense and highly fluorescent (at ca. 540 nm) dyes such as 1 by a directed chromophore–chromophore coupling. Molar extinction coefficients of more than 400 000 L mol−1 cm−1 are attained. R = CH(C6H13)2, CH(C7H15)2, CH(C9H19)2.