Investigating photoinduced energy and electron transfer mechanisms in ferrocene-zinc porphyrin-boron dipyrrin-fullerene supramolecular construct

Abstract

Photoinduced energy (EnT) and electron transfer (ET) processes have been the driving force in the conversion of solar energy to electrical energy or fuels. Understanding the mechanism is vital in designing “antenna-reaction centers” that mimic photosynthesis or further improve and stabilize the charge separated states.

In this study, the charge stabilizing property of a newly synthesized supramolecular construct of ferrocene-zinc porphyrin-boron dipyrrin-fullerene has been investigated through steady-state absorption, fluorescence emission, and transient absorption studies. The covalently linked ferrocene (Fc)-zinc porphyrin (ZnP)-boron dipyrrin (BDP) supramolecule was self-assembled with the imidazole appended fulleropyrrolidine (C60Im) through axial coordination allowing energy transfer (from BDP to ZnP) and stepwise electron transfer and hole transfer (from ZnP to C60Im, and from ZnP to Fc, respectively) or a stepwise electron transfer (from Fc to ZnP then from ZnP to C60Im) which has been established from time-resolved emission and transient absorption studies.