About this Research Topic
At the molecular level, light harvesting and transformation of the latter into redox energy is performed by a photosensitizer “PS”, whose electronic properties strongly impact the photo-induced processes. PS first absorbs a photon of appropriate energy which, very crudely, can promote an electron from the HOMO to the LUMO: transiently, as long as the excited state PS* lasts, there is thus a hole on the HOMO and an electron on the LUMO. The hole on the HOMO can be filled by an electron from a donor (reductive quenching) or the electron on the LUMO can be collected by an electron acceptor (oxidative quenching). Alternatively, transiently stored photonic energy can be transferred to a substrate and initiate a reaction.
PS thus plays a pivotal role in those photochemical processes. Very often, heavy metal based PS are chosen because they feature remarkable properties (long lifetimes, triplet reactivity, efficient light harvesting, tunable redox properties). Yet heavy metals are rare and toxic. A considerable amount of work has been devoted to the exploitation of Earth abundant metal complexes and purely organic photosensitizers. Many of them are comparable or even outcompete ruthenium and iridium sensitizers.
The goal of this Research Topic of Frontiers is to present to the broadest readership an account of the extraordinary possibilities offered by modern photochemistry in all the fields related to the conversion of light into redox energy, from fundamental research on photo-induced electron transfers to solar fuel production and more generally chemical bond formation, with a special focus on cheap yet robust photosensitizers.
We welcome Original Research, Review, Mini Review and Perspective articles on themes including, but not limited to:
• Design, synthesis and characterization of novel molecular earth-abundant metal complexes and organic photosensitizers
• Thermodynamics of photochemical steps in chemical reactions
• Theoretical investigations of the oxidative and reductive quenching mechanisms in different systems
• Green and renewable practices in organic photochemistry and photosensitizer development
• Fundamental and applied works on photo-induced electron transfer
Keywords: molecular photosensitizers, earth-abundant metal complexes, solar fuels, excited state properties, photo(redox)catalysis, oxidative/reductive quenching
Important Note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.