Excitation energy transfer and photo-induced electron transfer in axial bispyrenyl phosphorus porphyrin derivatives: factors governing the competition between energy and electron transfer processes under the existence of intramolecular π–π interaction

Abstract

In order to investigate the competition between energy and electron transfer processes, pyrene–phosphorus(V)porphyrin triads in which two pyrenes are connected to a central phosphorus atom through various bridges were synthesized. The triads have π–π interaction between the pyrene and the porphyrin moieties. As a result, emissions from the photo-excited states of pyrene and porphyrin were quenched through energy and/or electron transfer processes. In the relaxation from the excited state pyrene, the predominant process changed according to solvents and donor–acceptor distances.