Low-energy photoredox catalysis

Nature Reviews Chemistry, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 11, 2024

Language: Английский

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Detour to success: photoswitching via indirect excitation

Chemical Science, Journal Year: 2024, Volume and Issue: 15(30), P. 11684 - 11698

Published: Jan. 1, 2024

Photoswitching via indirect excitation allows harnessing low-energy photons to control molecular configuration. Herein, the state of art predominant photoswitching methods is presented.

Language: Английский

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Metal–Organic Bichromophore Lowers the Upconversion Excitation Power Threshold and Promotes UV Photoreactions

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(20), P. 11402 - 11414

Published: May 15, 2023

Sensitized triplet–triplet annihilation upconversion is a promising strategy to use visible light for chemical reactions requiring the energy input of UV photons. This avoids unsafe ultraviolet sources and can mitigate photo-damage provide access reactions, which filter effects hamper direct excitation. Here, we report new approach make blue-to-UV more amenable photochemical applications. The tethering naphthalene unit cyclometalated iridium(III) complex yields bichromophore with high triplet (2.68 eV) naphthalene-based reservoir featuring lifetime 72.1 μs, roughly factor 20 longer than photoactive excited state parent complex. In combination three different annihilators, consistently lower thresholds crossover from quadratic into linear excitation power dependence regime were observed compared system composed 2,5-diphenyloxazole annihilator sufficiently robust under long-term blue irradiation continuously high-energy singlet-excited that drive normally light. Both photoredox transfer catalyses feasible using this concept, including reductive N–O bond cleavage Weinreb amides, C–C coupling reaction based on aryl debromination, two Paternò–Büchi [2 + 2] cycloaddition reactions. Our work seems relevant in context developing strategies driving energetically demanding photochemistry low-energy

Language: Английский

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First‐Row d⁶ Metal Complex Enables Photon Upconversion and Initiates Blue Light‐Dependent Polymerization with Red Light

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(43)

Published: Sept. 8, 2023

Photosensitizers for sensitized triplet-triplet annihilation upconversion (sTTA-UC) often rely on precious heavy metals, whereas coordination complexes based abundant first-row transition metals are less common. This is mainly because long-lived triplet excited states more difficult to obtain 3d particularly when the d-subshell only partially filled. Here, we report first example of sTTA-UC a 3d6 metal photosensitizer yielding an performance competitive with metal-based analogues. Using newly developed Cr0 featuring equally good photophysical properties as OsII benchmark complex in combination acetylene-decorated anthracene annihilator, red-to-blue achievable. The efficiency under optimized conditions 1.8 %, and excitation power density threshold reach strong limit 5.9 W/cm2 . These factors, along high photostability, permit initiation acrylamide polymerization by red light, radiative energy transfer between delayed annihilator fluorescence blue light absorbing photo-initiator. Our study provides proof-of-concept photon elusive analogues widely employed d6 photosensitizers, their application photochemical reactions triggered wavelengths close near-infrared.

Language: Английский

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Red-Shifting Blue Light Photoredox Catalysis for Organic Synthesis: A Graphical Review

SynOpen, Journal Year: 2023, Volume and Issue: 07(01), P. 76 - 87

Published: Feb. 1, 2023

Abstract Photoredox catalysis has revolutionized synthetic chemistry in recent decades. However, the field traditionally used high-energy blue/ultraviolet light to activate chromophores. High-energy irradiation is associated with several drawbacks (e.g., activation of sensitive functional groups, undesired metal-ligand homolysis, background molecules, and poor penetration), which led researchers develop alternative systems lower energy deep red (DR) or near-infrared (NIR) light. This graphical review provides a concise overview photophysical principles relevant photoredox catalysis. Several applications that benefit from low-energy irradiation, such as large-scale batch reactions, photodynamic therapy, biological labeling, multi-photon excitation are reviewed.

Language: Английский

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Recent advancements in the molecular design of deep-red to near-infrared light-absorbing photocatalysts

Chem Catalysis, Journal Year: 2024, Volume and Issue: 4(8), P. 100973 - 100973

Published: April 17, 2024

Language: Английский

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Photocyclization by a triplet–triplet annihilation upconversion pair in water – avoiding UV-light and oxygen removal

Chemical Science, Journal Year: 2023, Volume and Issue: 14(40), P. 11040 - 11044

Published: Jan. 1, 2023

We present a formal [2 + 2]-cycloaddition of unsaturated ketones enabled by green-to-ultraviolet triplet-triplet annihilation upconversion (TTA-UC) pair, using commercially available Ru(bpy)32+ and pyrene as sensitizer annihilator, respectively. In the developed protocol, visible light irradiation at λmax = 520 nm allows for reaction to proceed without need UV-light aqueous medium eliminates oxygen removing protocols. Through this study, application readily pair is broadened include cyclization reactions. showcase utility system generating bicyclo[2.1.1]hexanes that are valuable bioisosteres ortho-substituted benzenes, promising motif pharmaceuticals.

Language: Английский

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Red-Light-Promoted Radical Cascade Reaction to Access Tetralins and Dialins Enabled by Zinc(II)porphyrin, A Light-Flexible Catalyst

Organic Letters, Journal Year: 2024, Volume and Issue: 26(18), P. 3929 - 3934

Published: April 26, 2024

[5,15-Bis(pentafluorophenyl)-10,20-diphenylporphinato]zinc(II) (1), a metalloporphyrin derivative that was recently reported as an efficient photocatalyst driven by blue LEDs our group, found to catalyze red-light-promoted (630 nm LEDs) radical cascade reaction of N-3-arylpropionyloxyphthalimides with radicophiles including electron-deficient alkenes and alkynes, providing access range functionalized tetralin dialin derivatives. The catalyzed 1 took place via oxidative quenching cycle in DMSO, where no sacrificial electron donor required, uncovering unique solvent effect capable promoting the porphyrin catalysis.

Language: Английский

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Steric and Electronic Influence of Excited-State Decay in Cu(I) MLCT Chromophores

Accounts of Chemical Research, Journal Year: 2024, Volume and Issue: 57(19), P. 2872 - 2886

Published: Sept. 11, 2024

ConspectusFor the past 11 years, a dedicated effort in our research group focused on fundamentally advancing photophysical properties of cuprous

Language: Английский

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Π‐Radical Photosensitizer for Highly Efficient and Stable Near‐Infrared Photon Upconversion

Advanced Optical Materials, Journal Year: 2023, Volume and Issue: 12(6)

Published: Sept. 10, 2023

Abstract Near‐infrared (NIR)‐to‐blue triplet–triplet annihilation upconversion (TTA‐UC) exhibits substantial potential for diverse applications, encompassing photovoltaics, photocatalysis, bioimaging, and photodynamic therapy. A major challenge in this field, however, is attaining high quantum yields ( Φ UC ) without using transition metals as NIR photosensitizers. This research presents an innovative organic π‐radical photosensitizer (TTM‐TPA) featuring extended absorption the region (≈760 nm) that capable of generating pronounced anti‐Stokes emissions when coupled with suitable triplet acceptors. By eliminating energy loss associated intersystem crossing promoting rapid doublet–triplet transfer processes, binary TTM‐TPA/perylene system achieves values up to 6.8% shift 0.93 eV. Notably, TTA‐UC demonstrates exceptional stability subjected intense 733 nm laser irradiation (4 W cm −2 ), maintaining nearly constant intensity after 4 h. These findings underscore considerable doublet‐sensitized a broad array practical applications.

Language: Английский

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