Insights into the intricate charge photoaccumulation in a polyoxometalate–bodipy covalent hybrid

Solar fuel generation relies on the catalysis of multielectron, multiproton reactions facilitated in nature by charge accumulation in electron relays like NADPH or hydroquinone. Here, we demonstrate the light-driven charge accumulation in a noble-metal-free photochemical dyad comprising a bodipy pho...

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Detalles Bibliográficos
Autores: Cariño, Christian, Moussa, Naguy, Blanchard, Sébastien, Solé-Daura, Albert, Proust, Anna, Izzet, Guillaume
Tipo de recurso: artículo
Fecha de publicación:2025
País:España
Institución:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Repositorio:Recercat. Dipósit de la Recerca de Catalunya
OAI Identifier:oai:recercat.cat:2072/487034
Acceso en línea:http://hdl.handle.net/2072/487034
https://doi.org/10.1039/D5QI01202C
Access Level:acceso embargado
Palabra clave:Química
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Descripción
Sumario:Solar fuel generation relies on the catalysis of multielectron, multiproton reactions facilitated in nature by charge accumulation in electron relays like NADPH or hydroquinone. Here, we demonstrate the light-driven charge accumulation in a noble-metal-free photochemical dyad comprising a bodipy photosensitizer linked to a Dawson polyoxometalate (POM) using triethylamine (TEA) as sacrificial electron donor. Under visible light irradiation, the hybrid dyad accumulates up to two electrons on the POM, achieving complete conversion within few minutes. The first reduction proceeds rapidly and efficiently while the second electron is introduced more slowly through an intricate, multi-pathway mechanism that we inferred through combined spectroscopy, electrochemistry and theoretical calculations. The formation of the two-electron reduced species is enhanced in the presence of trifluoroacetic acid by virtue of proton-coupled electron transfer (PCET) as well as by promoting the dismutation of the one-electron reduced POM. Simultaneously, POM reduction may also take place via a light-independent route involving the reactive TEA radical byproduct, effectively rendering TEA an overall two-electron, one-proton donor. The stored redox equivalents in the POM were demonstrated to activate oxygen but also to be engaged in PCET to substrates such as 1,4-benzoquinone, highlighting the potential utility of POM–photosensitizer hybrids in solar fuel-related transformations.