Abstract One-photon-absorbing photosensitizers are commonly used in homogeneous photocatalysis which require the absorption of ultraviolet (UV) /visible light to populate the desired excited states with adequate energy and lifetime. Nevertheless, the limited penetration depth and competing absorption by organic substrates of UV/visible light calls upon exploring the utilization of longer-wavelength irradiation, such as near-infrared light (λ irr > 700 nm). Despite being found applications in photodynamic therapy and bioimaging, two-photon absorption (TPA), the simultaneous absorption of two photons by one molecule, has been rarely explored in homogeneous photocatalysis. Herein, we report a group of ruthenium polypyridyl complexes possessing TPA capability that can drive a variety of organic transformations upon irradiation with 740 nm light. We demonstrate that these TPA ruthenium complexes can operate in an analogous manner as one-photon-absorbing photosensitizers for both energy-transfer and photoredox reactions, as well as function in concert with a transition metal co-catalyst for metallaphotoredox C–C coupling reactions.
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Synthesis of a light-harvesting ruthenium porphyrin complex substituted with BODIPY units. Implications for visible light-promoted catalytic oxidations
A light-harvesting ruthenium porphyrin substituted covalently with four boron–dipyrrin (BODIPY) moieties has been synthesized and studied. The resulting complex showed an efficient decarbonylation reaction predominantly due to a photo-induced energy transfer process. Chemical oxidation of the ruthenium( ii ) BODIPY–porphyrin afforded a high-energy trans -dioxoruthenium( vi ) species that is one order of magnitude more reactive towards alkene oxidation than those analogues supported by conventional porphyrins. In the presence of visible light, the ruthenium( ii ) BODIPY–porphyrin displayed remarkable catalytic activity toward sulfide oxidation and alkene epoxidation using iodobenzene diacetate [PhI(OAc) 2 ] and 2,6-dichloropyridine N -oxide (Cl 2 pyNO) as terminal oxidants, respectively. The findings in this work highlight that porphyrin–BODIPY conjugated metal complexes are potentially useful for visible light-promoted catalytic oxidations.
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- Award ID(s):
- 1764315
- PAR ID:
- 10253246
- Date Published:
- Journal Name:
- New Journal of Chemistry
- Volume:
- 45
- Issue:
- 11
- ISSN:
- 1144-0546
- Page Range / eLocation ID:
- 4977 to 4985
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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