Towards Molecular Logic and Artificial Photosynthesis

Artificial Photosynthetic Reaction Center Exhibiting Acid-Responsive Regulation of Photoinduced Charge Separation

“…Just as NPQ is vital to the survival of plants, realizing self-regulation of photoinduced ET efficiency may be necessary to maximize the lifespans of artificial photosynthetic solar energy conversion devices. − There are few reported examples of self-regulating molecules that model biological photoprotective behavior. , An antenna composed of five zinc porphyrins linked to a rhodamine dye is the only artificial photosynthetic system that exhibits acid-responsive self-regulation of its excited-state lifetime as found in NPQ . Protonation of the otherwise photochemically passive dye yields its open form, which is an excellent Förster-type energy acceptor for and therefore quencher of the associated porphyrin excited singlet states.…”

Control over Photoinduced Energy and Electron Transfer in Supramolecular Polyads of Covalently linked azaBODIPY-Bisporphyrin ‘Molecular Clip’ Hosting Fullerene

“…Biomimetic artificial photosynthetic systems aimed at solar energy conversion and fuel production must integrate modular molecular entities to collect and funnel light energy, generate charge-separated species, and transport the generated chemical energy to the catalytic sites for water oxidation and CO 2 reduction, similar to the natural photosynthetic systems . Over the years, extensive efforts have been devoted to tackle every facet of this complex problem by molecularly engineering the supramolecular systems; however, components that are both efficient and robust and integrated into one working system remain a major challenge. − Novel design of light-funneling, photoconversion, and catalytic modules capable of self-ordering and self-assembling into an integrated functional unit will make an efficient artificial photosynthetic system possible. , …”

“…The three-dimensional electron acceptors, fullerenes, have stimulated interest due to their extraordinary electron acceptor properties that was predicted theoretically and confirmed experimentally. − Supramolecular systems involving a variety of electron donors (such as porphyrin, phthalocyanine, etc.) and fullerene have made considerable advances in the areas of light-induced electron-transfer chemistry and light energy harvesting. − ,− These breakthroughs are mainly due to the small reorganization energy of fullerenes in electron-transfer reactions that would lead to ultrarapid charge separation together with slow charge recombination leading unprecedentedly long-lived charge-separated states with high quantum efficiencies. , Additionally, such studies have shed light on fundamental understanding of electron-transfer aspects, such as distance and orientation factors related to supramolecular organization, electronic coupling elements, reorganization energies, electron tunneling, etc. − ,− …”