Photosynthetic Donor-Acceptor Mimicry Using Near-Infrared Photosensitizers

Supramolecular multi-modular donor-acceptor systems constructed using different photo- and redox-active species have been extensively investigated in the last three decades.  With suitably designed and assembled modular systems, these supramolecules have found useful in solar-fuel and solar-electricity generation and in building optoelectronic devices.  Traditionally, porphyrins and phthalocyanines have extensively been used as light-harvesting and electron-transfer units in these multi-modular systems performing photoinduced energy- and electron-transfer reactions. Recently, BF₂-chelated dipyrromethene (BODIPY) dyes, and their structural analogs have emerged as efficient and tunable light-absorption and luminescent species.  The present contribution summarizes our recent progress in the design, synthesis, electrochemistry, and photochemistry of donor-acceptor hybrids derived from BODIPY and azaBODIPY photosensitizers with emphasis on radical ion-pair formation.