Visible‐Light Induced Fixation of SO₂ into Organic Molecules with Polypyridine Chromium(III) Complexes

ChemCatChem, Год журнала: 2023, Номер 15(6)

Опубликована: Янв. 23, 2023

Abstract Incorporation of sulfur dioxide into organic compounds is achieved by a photocatalytic approach using sensitizers made from earth‐abundant chromium(III) ions and visible light leading to sulfones sulfonamides. We employed three different [Cr(ddpd) 2 ] 3+ , [Cr(bpmp) [Cr(tpe) with long excited state lifetimes ground redox potentials as well varying stability under the reaction conditions (ddpd= N N’ ‐dimethyl‐ ’‐dipyridin‐2‐yl‐pyridine‐2,6‐diamine; bpmp=2,6‐bis(2‐pyridylmethyl)pyridine; tpe=1,1,1‐tris(pyrid‐2‐yl)ethane). Key steps catalytic cycles are identified electrochemical, luminescence quenching, photolysis, laser flash photolysis experiments delivering detailed picture challenges in these transformations. The reactivity reduced chromium complex was key property explain outcomes. Initial cage escape yield determinations revealed that desired photoreactions occur unusually high quantum efficiencies, whereas side reactions almost unproductive.

Язык: Английский

---

Factors that Impact Photochemical Cage Escape Yields

Chemical Reviews, Год журнала: 2024, Номер 124(11), С. 7379 - 7464

Опубликована: Май 14, 2024

The utilization of visible light to mediate chemical reactions in fluid solutions has applications that range from solar fuel production medicine and organic synthesis. These are typically initiated by electron transfer between a photoexcited dye molecule (a photosensitizer) redox-active quencher yield radical pairs intimately associated within solvent cage. Many these radicals undergo rapid thermodynamically favored "geminate" recombination do not diffuse out the cage surrounds them. Those escape useful reagents may subsequent important above-mentioned applications. process factors determine yields remain poorly understood despite decades research motivated their practical fundamental importance. Herein, state-of-the-art on light-induced appeared since seminal 1972 review J. P. Lorand entitled "The Cage Effect" is reviewed. This also provides some background for those new field discusses both homolytic bond photodissociation bimolecular induced reactions. concludes with key goals directions future promise elevate this very vibrant even greater heights.

Язык: Английский

---

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

---

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

---

Molecular ruby: exploring the excited state landscape

Dalton Transactions, Год журнала: 2022, Номер 51(17), С. 6519 - 6525

Опубликована: Янв. 1, 2022

The discovery of the highly NIR-luminescent molecular ruby [Cr(ddpd)2]3+ (ddpd = N,N'-dimethyl-N,N'-dipyridin-2-ylpyridine-2,6-diamine) has been a milestone in development earth-abundant luminophors and led to important new impulses field spin-flip emitters. Its favourable optical properties such as high photoluminescence quantum yield long excited state lifetime are traced back remarkable landscape which investigated great detail. This article summarises results these studies with aim create coherent picture ordering ultrafast well long-timescale dynamics. Additional experimental data is provided fill gaps left by previous reports.

Язык: Английский

---

Bimolecular reactivity of 3d metal-centered excited states (Cr, Mn, Fe, Co)

Chemical Physics Reviews, Год журнала: 2022, Номер 3(4)

Опубликована: Ноя. 9, 2022

Metal-centered (MC) excited states (ESs) of 3d transition metal complexes (TMCs) often possess rather low energies so that these represent the lowest energy ESs. Additionally, MC are strongly distorted, hence they efficiently decay non-radiatively to ground state. As bimolecular photoinduced electron transfer (PET) and (EnT) processes require contact substrate, confinement ES wavefunction makes challenging. Consequently, considered less useful as compared long-lived charge higher with wavefunctions extending onto ligands. Despite supposed drawbacks, some classes TMCs can successfully engage in PET EnT being photoactive states. We discuss initial examples reactivity covering chromium, manganese, iron, cobalt aim gain a deeper understanding identify decisive key parameters. Finally, we present catalytic photoredox using photosensitizers suitable

Язык: Английский

---

Synergistic dual-mechanism fluorescence quenching immunochromatographic assay based on Fe-polydopamine submicrobeads for sensitive detection of enrofloxacin

Chemical Engineering Journal, Год журнала: 2022, Номер 454, С. 140444 - 140444

Опубликована: Ноя. 16, 2022

Язык: Английский

---

Stable Molybdenum(0) Carbonyl Complex for Upconversion and Photoredox Catalysis

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(30), С. 16597 - 16609

Опубликована: Июль 21, 2023

Photoactive complexes with earth-abundant metals have attracted increasing interest in the recent years fueled by promise of sustainable photochemistry. However, sophisticated ligands complicated syntheses are oftentimes required to enable photoactivity nonprecious metals. Here, we combine a cheap metal simple easily access photoactive complex. Specifically, synthesize molybdenum(0) carbonyl complex Mo(CO)3(tpe) featuring tripodal ligand 1,1,1-tris(pyrid-2-yl)ethane (tpe) two steps high overall yield. The shows intense deep-red phosphorescence excited state lifetimes several hundred nanoseconds. Time-resolved infrared spectroscopy and laser flash photolysis reveal triplet metal-to-ligand charge-transfer (3MLCT) as lowest state. Temperature-dependent luminescence complemented density functional theory (DFT) calculations suggest thermal deactivation 3MLCT via higher lying metal-centered states analogy well-known photophysics [Ru(bpy)3]2+. Importantly, found that title compound is very photostable due lack labilized Mo-CO bonds (as caused trans-coordinated CO) facial configuration ligands. Finally, show versatility applications: (1) green-to-blue photon upconversion triplet-triplet annihilation mechanism (2) photoredox catalysis for green-light-driven dehalogenation reaction. Overall, our results establish promising design strategy stable avoiding tedious multistep syntheses.

Язык: Английский

---

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

---

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

---