| 1. |
- Bericat Vadell, Robert, et al.
(författare)
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Single-electron transfer reactions on surface-modified gold plasmons
- 2023
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Ingår i: Materials Today Chemistry. - : Elsevier. - 2468-5194. ; 34
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Tidskriftsartikel (refereegranskat)abstract
- Photoredox catalysis's relevance in organic synthesis research and innovation will increase in the coming decades. However, the processes rely almost exclusively on expensive noble metal complexes, most notably iridium complexes, to absorb light and transfer a single charge to a substrate or a catalyst to initiate cascade transformations. Light-triggered plasmon resonances generate a non-Fermi-Dirac energy distribution with many hot carriers that decay in similar to 1 ps. Their ultrafast relaxation makes performing single electron transfer (SET) transformations challenging. Herein, a novel photosystem is proposed based on surface-modified gold nanoparticles (aka plasmon "molecularization"), which improved charge separation and, more importantly, enabled SET reactions, expanding the portfolio of photocatalysts available for photoredox catalysis. The photosystem was made into an electrode, permitting its use in photoelectrochemical arrangements that leverage electro- and photo-chemical approaches' benefits and chemical engineering solutions, helping the synthetic chemistry efforts towards greener synthesis and synthesis of more complex structures on a scale.
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| 2. |
- Patehebieke, Yerseen, et al.
(författare)
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β-Scission of Secondary Alcohols via Photosensitization : Synthetic Utilization and Mechanistic Insights
- 2024
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Ingår i: ACS Catalysis. - : American Chemical Society (ACS). - 2155-5435. ; 14:1, s. 585-593
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Tidskriftsartikel (refereegranskat)abstract
- An efficient metal-free photocatalytic method for the alkylation of alkenes using accessible aliphatic alcohols as redox auxiliaries is presented. C-centered radicals can be generated under mild conditions and subsequently employed in a C(sp3)-C(sp3) bond-forming process, which overall provides a C1 tethering strategy of nucleophiles and electrophiles. The optimized conditions accommodate various electron-deficient alkenes and secondary/tertiary alcohols, with applications in late-stage functionalization of natural products and pharmaceutically relevant compounds. Mechanistic investigations revealed a complex mechanistic manifold, including non-PCET fragmentation and concerted/stepwise PCET. Even though the previously thought PCET type mechanism is compatible with our observations, the non-PCET mechanism most probably constitutes a main pathway.
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| 3. |
- Sekar, Pandiaraj, et al.
(författare)
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Decoupling Plasmonic Hot Carrier from Thermal Catalysis via Electrode Engineering
- 2024
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Ingår i: NANO LETTERS. - : American Chemical Society (ACS). - 1530-6984 .- 1530-6992. ; 24:28, s. 8619-8625
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Tidskriftsartikel (refereegranskat)abstract
- Increased attention has been directed toward generating nonequilibrium hot carriers resulting from the decay of collective electronic oscillations on metal known as surface plasmons. Despite numerous experimental endeavors, demonstrating hot carrier-mediated photocatalysis without a heating contribution has proven challenging, particularly for single electron transfer reactions where the thermal contribution is generally detrimental. An innovative engineering solution is proposed to enable single electron transfer reactions with plasmonics. It consists of a photoelectrode designed as an energy filter and photocatalysis performed with light function modulation instead of continuously. The photoelectrode, consisting of FTO/TiO2 amorphous (10 nm)/Au nanoparticles, with TiO2 acting as a step-shape energy filter to enhance hot electron extraction and charge-separated state lifetime. The extracted hot electrons were directed toward the counter electrode, while the hot holes performed a single electron transfer oxidation reaction. Light modulation prevented local heat accumulation, effectively decoupling hot carrier catalysis from the thermal contribution.
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