Abstract:
In natural photosynthesis two major processes, absorption of light energy by antenna system and transportation of that light energy to the reaction center take place efficiently. There is a growing interest to mimic these processes in artificial systems with an ultimate aim of harvesting solar energy. In the present study, we wish to report novel molecular triads comprised of boron dipyrrin-fullerene dyad covalently linked to either an energy donating entity (En-D1-A type triads) or a secondary electron donating entity (D2-D1-A type triads) to probe sequential energy/electron transfer events. Anthracene, pyrene, fluorene and naphthalene are chosen to be energy donating (En) entities while ferrocene and triphenylamine entities are chosen as secondary electron donors (D2 - hole transfer agents) (see Scheme 1 below). Systematic spectral, electrochemical and emission studies are performed to probe sequential energy transfer followed by electron transfer events in the newly synthesized triads. Computational studies using B3LYP/3-21G* are performed to arrive at the geometry and electronic structures. Photochemical study using time-resolved emission is performed to probe electron transfer events. Further, organic photocells are being built to directly convert light energy into electricity.
