Recent advances in triplet–triplet annihilation upconversion and singlet fission, towards solar energy applications

Energy & Environmental Science, Год журнала: 2022, Номер 15(12), С. 4982 - 5016

Опубликована: Янв. 1, 2022

Here we consolidate recent advances in the fields of triplet–triplet annihilation photon upconversion and singlet fission. We further describe their utility increasing efficiency photovoltaic devices.

Язык: Английский

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Blue‐to‐UVB Upconversion, Solvent Sensitization and Challenging Bond Activation Enabled by a Benzene‐Based Annihilator

Angewandte Chemie International Edition, Год журнала: 2022, Номер 62(8)

Опубликована: Ноя. 18, 2022

Several energy-demanding photoreactions require harsh UV light from inefficient sources. The conversion of low-energy visible to high-energy singlet states via triplet-triplet annihilation upconversion (TTA-UC) could offer a solution for driving such reactions under mild conditions. We present the first annihilator with an emission maximum in UVB region that, combined organic sensitizer, is suitable blue-to-UVB upconversion. was successfully employed as energy donor subsequent FRET activations aliphatic carbonyls. This hitherto unreported UC-FRET reaction sequence directly monitored using laser spectroscopy and applied mechanistic irradiation experiments demonstrating feasibility Norrish chemistry. Our results provide clear evidence novel blue light-driven substrate or solvent activation strategy, which important context developing more sustainable light-to-chemical systems.

Язык: Английский

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Direct Observation of Triplet States in the Isomerization of Alkenylboronates by Energy Transfer Catalysis

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(39), С. 21576 - 21586

Опубликована: Сен. 20, 2023

Alkenylboronates are versatile building blocks for stereocontrolled synthesis owing to the traceless nature of boron group that can be leveraged achieve highly selective geometric isomerization. Using thioxanthone as an inexpensive photocatalyst, photoisomerization these species continues provide expansive platform stereodivergent synthesis, particularly in construction bioactive polyenes. Although mechanistic investigations consistent with light-driven energy transfer, direct experimental evidence remains conspicuously absent. Herein, we report a rigorous investigation using two widely used alkenylboronates alongside relevant reference compounds. Through combination irradiation experiments, transient absorption spectroscopic studies, kinetic modeling, and DFT calculations all isomers model compounds, it has been possible unequivocally detect characterize perpendicular triplet generated by transfer. Our results serve not only blueprint studies challenging organic sensitizers, but guidelines delineated have also enabled development more sustainable reaction conditions: first time, efficient organocatalytic isomerization under sunlight become feasible.

Язык: Английский

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Structurally Flexible Au–Cu Alloy Nanoclusters Enabling Efficient Triplet Sensitization and Photon Upconversion

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(12), С. 6994 - 7004

Опубликована: Март 20, 2023

Ligand-protected noble-metal nanoclusters exhibit an innately triplet nature and have been recently recognized as emerging platforms for sensitizers of photon upconversion (UC) via triplet-triplet annihilation. Herein, we report that a structurally flexible Au-Cu alloy nanocluster, [Au4Cu4(S-Adm)5(DPPM)2]+ (Au4Cu4; S-Adm = 1-adamantanethiolate, DPPM bis(diphenylphosphino)methane), exhibited favorable sensitizer properties superior UC performance. Contrary to the rigid Au2Cu6(S-Adm)6(TPP)2 (Au2Cu6, TPP triphenylphosphine), Au4Cu4 significantly better characteristics, such near-unity quantum yield intersystem crossing (ISC), long lifetime (ca. 8 μs), efficient energy transfer (TET). The ISC was attributed practically negligible activation barriers during process, which caused by spin-orbit interaction between two isoenergetic isomers predicted theoretical calculations. A series aromatic molecules with different energies were used acceptors reveal driving force dependence TET rate constant (kTET). This dependency analyzed evaluate sensitization ability nanoclusters. results showed maximum value kTET seven times larger than Au2Cu6, presumably reflects structural/electronic fluctuations state residence. combination 9,10-diphenylanthracene (DPA) annihilator/emitter achieved internal yields 14% (out 50% maximum) extremely low threshold intensities (2-26 mWcm-2). performance far exceeds Au2Cu6 is also outstanding among organic-inorganic hybrid nanomaterials reported so far.

Язык: Английский

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Triplet–triplet annihilation-based photon upconversion using nanoparticles and nanoclusters

Materials Horizons, Год журнала: 2024, Номер 11(10), С. 2304 - 2322

Опубликована: Янв. 1, 2024

The phenomenon of photon upconversion (UC), generating high-energy photons from low-energy photons, has attracted significant attention. In particular, triplet-triplet annihilation-based UC (TTA-UC) been achieved by combining the excitation states two types molecules, called sensitizer and emitter (or annihilator). With TTA-UC, it is possible to convert weak, incoherent near-infrared (NIR) light, which constitutes half solar radiation intensity, into ultraviolet visible light that are suitable for operation light-responsive functional materials or devices such as cells photocatalysts. Research on TTA-UC being conducted worldwide, often employing with high intersystem crossing rates, metal porphyrins, sensitizers. This review summarizes recent research trends in triplet energy transfer semiconductor nanoparticles nanocrystals diameters nanometer range, also known quantum dots, ligand-protected nanoclusters, have even smaller well-defined sub-nanostructures. Concerning nanoparticles, transmitter ligands applied surface efficiently excitons formed inside emitters. Applications expanding solid-state NIR light. Additionally, there active development sensitizers using more cost-effective environmentally friendly elements. Regarding methods established evaluation excited states, deepening understanding luminescent properties relaxation processes.

Язык: Английский

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Iron(III) Carbene Complexes with Tunable Excited State Energies for Photoredox and Upconversion

Journal of the American Chemical Society, Год журнала: 2024, Номер unknown

Опубликована: Апрель 10, 2024

Substituting precious elements in luminophores and photocatalysts by abundant first-row transition metals remains a significant challenge, iron continues to be particularly attractive owing its high natural abundance low cost. Most complexes known date face severe limitations due undesirably efficient deactivation of luminescent photoredox-active excited states. Two new iron(III) with structurally simple chelate ligands enable straightforward tuning ground state properties, contrasting recent examples, which chemical modification had minor impact. Crude samples feature two luminescence bands strongly reminiscent complex, this observation was attributed dual luminescence, but our case, there is clear-cut evidence that the higher-energy stems from an impurity only red photoluminescence doublet ligand-to-metal charge transfer (2LMCT) genuine. Photoinduced oxidative reductive electron reactions methyl viologen 10-methylphenothiazine occur nearly diffusion-limited kinetics. Photocatalytic not previously reported for compound class, particular C–H arylation diazonium salts aerobic hydroxylation boronic acids, were achieved low-energy light excitation. Doublet–triplet energy (DTET) 2LMCT anthracene annihilator permits proof principle triplet–triplet annihilation upconversion based on molecular photosensitizer. These findings are relevant development featuring photophysical photochemical properties competitive noble-metal-based compounds.

Язык: Английский

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Triplet properties and intersystem crossing mechanism of PtAg28 nanocluster sensitizers achieving low threshold and efficient photon upconversion

Nanoscale, Год журнала: 2024, Номер 16(6), С. 3053 - 3060

Опубликована: Янв. 1, 2024

The combination of the PtAg28 nanocluster sensitizer with a 9,10-diphenylanthracene emitter achieved low upconversion threshold 0.8 mW cm −2 at 532 nm excitation, along efficient under 1-sun conditions.

Язык: Английский

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Triplet Upconversion under Ambient Conditions Enables Digital Light Processing 3D Printing

ACS Central Science, Год журнала: 2024, Номер 10(2), С. 272 - 282

Опубликована: Янв. 16, 2024

The rapid photochemical conversion of materials from liquid to solid (i.e., curing) has enabled the fabrication modern plastics used in microelectronics, dentistry, and medicine. However, industrialized photocurables remain restricted unimolecular bond homolysis reactions (Type I photoinitiations) that are driven by high-energy UV light. This narrow mechanistic scope both challenges production high-resolution objects restricts can be produced using emergent manufacturing technologies (e.g., 3D printing). Herein we develop a photosystem based on triplet-triplet annihilation upconversion (TTA-UC) efficiently drives Type photocuring process green light at low power density (<10 mW/cm2) presence ambient oxygen. system also exhibits superlinear dependence its cure depth exposure intensity, which enhances spatial resolution. enables for first-time integration TTA-UC an inexpensive, rapid, process, digital processing (DLP) printing. Moreover, relative traditional II (photoredox) strategies, present photoinitiation method results improved confinement resin shelf stability. report provides user-friendly avenue utilize processes paves way toward next-generation with geometric precision functionality.

Язык: Английский

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

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(20), С. 11402 - 11414

Опубликована: Май 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

Язык: 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, Год журнала: 2023, Номер 62(43)

Опубликована: Сен. 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.

Язык: Английский

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