Photoinduced energy and electron transfer in 1,8-naphthalimide-corrole dyads

A series of corrole-1,8-naphthalimide dyads has been synthesized. The dyads were assembled in a convergent fashion from two fragments via a corrole forming reaction. Central to the success of the synthetic strategy was the preparation of suitably functionalized derivatives of naphthalene-1,8-carboxymide. Six different dyads possessing either a different linker (a meta-phenylene or a para-phenylmethylene) or a corrole with different substituents at the 5 and 15 positions were prepared. A photophysical and spectroscopic characterization of the dyads and the reference models show that whereas upon selective excitation of the corrole component no photo-induced process occurs, excitation of the naphthalimide unit results in very efficient energy or electron transfer processes. The electron transfer contributes to the quenching process with a ratio between 0% and 85% depending on the nature of the corrole accepting unit. The processes are discussed in the frame of current theories. This is the first report of stable corrole-based dyads with interesting photo-activity at ambient temperature.