Characterization of A π–π stacking cocrystal of 4-nitrophthalonitrile directed toward application in photocatalysis

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: Feb. 16, 2024

Abstract Photoexcitation of the electron-donor-acceptor complexes have been an effective approach to achieve radicals by triggering electron transfer. However, catalytic version complex photoactivation is quite underdeveloped comparing well-established utilization electronically biased partners. In this work, we utilize 4-nitrophthalonitrile as acceptor facilitate efficient π-stacking with electron-rich aromatics form complex. The characterization and energy profiles on cocrystal 1,3,5-trimethoxybenzene disclose that transfer highly favorable under light irradiation. This catalyst can be efficiently applied in benzylic C−H bond developing Giese reaction alkylanisoles oxidation benzyl alcohols. A broad scope tolerated a mechanism also proposed. Moreover, corresponding π-anion interaction potassium formate further hydrocarboxylation alkenes efficiently.

Language: Английский

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Computational tools for the simulation and analysis of spin-polarized EPR spectra

Journal of Magnetic Resonance, Journal Year: 2023, Volume and Issue: 349, P. 107410 - 107410

Published: Feb. 24, 2023

The EPR spectra of paramagnetic species induced by photoexcitation typically exhibit enhanced absorptive and emissive features resulting from sublevel populations that differ thermal equilibrium. the spin polarization are dictated selectivity photophysical process generating observed state. Simulation spin-polarized is crucial in characterization both dynamics formation photoexcited state as well its electronic structural properties. EasySpin, simulation toolbox for spectroscopy, now includes extended support states arbitrary multiplicity formed a variety different mechanisms, including triplet populated intersystem crossing, charge recombination or transfer, spin-correlated radical pairs created photoinduced electron singlet fission multiplet arising systems containing chromophores stable radicals. In this paper, we highlight EasySpin's capabilities on basis illustrative examples literature fields ranging across chemistry, biology, material science quantum information science.

Language: Английский

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Organic Donor‐Acceptor Systems for Photocatalysis

Advanced Science, Journal Year: 2023, Volume and Issue: 11(10)

Published: Dec. 25, 2023

Abstract Organic semiconductor materials are considered to be promising photocatalysts due their excellent light absorption by chromophores, easy molecular structure tuning, and solution‐processable properties. In particular, donor‐acceptor (D‐A) type organic photocatalytic synthesized introducing D A units intra‐ or intermolecularly, have made great progress in studies. More more studies demonstrated that the D‐A combine effective carrier separation, tunable bandgap, sensitive optoelectronic response, an strategy for enhancing absorption, improving exciton dissociation, optimizing transport. This review provides a thorough overview of strategies aimed at performance semiconductors. Initially, essential methods modifying materials, such as interface engineering, crystal interaction modulation, briefly discussed. Subsequently, delves into various based on intramolecular intermolecular interactions, encompassing small molecules, conjugated polymers, crystalline supramolecules, heterojunctions. Meanwhile, energy band structures, dynamics, redox‐active sites under different bonding modes Finally, highlights advanced applications photocatalystsand outlines prospective challenges opportunities.

Language: Английский

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Long-Lived Charge Separation in Single Crystals of an Electron Donor Covalently Linked to Four Acceptor Molecules

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(14), P. 9911 - 9919

Published: March 26, 2024

Crystalline donor–acceptor (D–A) systems serve as an excellent platform for studying CT exciton creation, migration, and dissociation into free charge carriers solar energy conversion. Donor–acceptor cocrystals have been utilized to develop understanding of formation in ordered organic solids; however, the strong electronic coupling D A units can sometimes limit separation lifetimes due their close proximity. Covalent D–A that preorganize specific structures assist engineering crystal morphologies promote long-lived overcome this limitation. Here we investigate photogenerated a single 2,5,8,11-tetraphenylperylene (PerPh4) donor which four identical naphthalene-(1,4:5,8)-bis(dicarboximide) (NDI) electron acceptors are covalently attached at para positions PerPh4 phenyl groups yield PerPh4-NDI4. X-ray crystallography shows NDIs pack pairwise two distinct motifs. Two NDI one PerPh4-NDI4 positioned over donors adjacent molecules with acceptor π-systems having large dihedral angle between them, while other form xylene-NDI van der Waals π-stacks corresponding molecules. Upon selective photoexcitation crystal, occurs <300 fs yielding electron–hole pairs live more than ∼16 μs. This demonstrates effectiveness linked efficient

Language: Английский

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Resonance-Induced Dynamic Triplet Exciton Population for Photoactivated Organic Ultralong Room Temperature Phosphorescence

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(29), P. 20449 - 20457

Published: July 11, 2024

Dynamically populating triplet excitons under external stimuli is desired to develop smart optoelectronic materials, but it remains a formidable challenge. Herein, we report resonance-induced excited state regulation strategy dynamically modulate the exciton population by introducing self-adaptive N-C═O structure phosphors. The developed phosphors activated high-power ultraviolet irradiation exhibited enhanced photoactivated organic ultralong room temperature phosphorescence (PA-OURTP) with lifetimes of up ∼500 ms. PA-OURTP was ascribed resonance variation-induced intersystem crossing generate excess excitons. excellent performance and deactivation time ambient conditions materials could function as reusable recorded medium for time-sensitive information encryption through optical printing. This study provides an effective approach regulating offers valuable guidance high-performance security printing applications.

Language: Английский

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Recent advances in organic donor–acceptor cocrystals: design, synthetic approaches, and optical applications

CrystEngComm, Journal Year: 2023, Volume and Issue: 25(21), P. 3126 - 3141

Published: Jan. 1, 2023

The recent progress in optical applications of organic donor–acceptor co-crystals is reviewed terms material design, synthetic approach and future perspectives.

Language: Английский

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Achieving pure room temperature phosphorescence (RTP) in phenoselenazine-based organic emitters through synergism among heavy atom effect, enhanced n → π* transitions and magnified electron coupling by the A–D–A molecular configuration

Chemical Science, Journal Year: 2024, Volume and Issue: 15(24), P. 9112 - 9119

Published: Jan. 1, 2024

Synergism among heavy atom effect, enhanced n → π* transitions and magnified electron coupling to promote pure RTP emission.

Language: Английский

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Structure-Dependent Triplet State Formation in Fluorinated Perylenediimide Single Crystal Polymorphs

The Journal of Physical Chemistry C, Journal Year: 2024, Volume and Issue: 128(4), P. 1603 - 1611

Published: Jan. 17, 2024

Perylenediimide (PDI) and its derivatives have garnered significant attention as promising n-type semiconductors to replace fullerenes acceptors in organic photovoltaic cells (OPVs). However, the aggregation tendencies rapid excimer formation of PDIs hindered their efficiency OPVs. To address this issue enhance solubility while fine-tuning electronic properties, researchers explored fluorination strategies. In study, we investigate structure–function relationship two crystalline N,N-bis(2′,2′,3′,3′,4′,4′,5′,5′,6′,6′,7′,7′,8′,8′,8′-pentadecafluorooctan-1-yl)perylene(3,4:9,10)bis(dicarboximide) (FPDI) polymorphs, namely, FPDI-α FPDI-β. Their crystal structures show that π systems FPDI molecules adopt an orthogonal geometry, those FPDI-β are parallel slip-stacked. We report excited state dynamics using transient absorption fluorescence microscopy time-resolved electron paramagnetic resonance spectroscopy. Upon photoexcitation, both polymorphs exhibit a lowest singlet (S1) with substantial charge transfer (CT) character. This S1-CT decays τ = 350 ps form triplet via spin–orbit charge-transfer intersystem crossing near-quantitative yield, back ground 140 ps. study illustrates influence different packing motifs on photoinduced intermolecular CT processes single crystals same molecule contributes understanding role optimizing PDI-based molecular materials for solid state.

Language: Английский

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Oriented Triplet Excitons as Long-Lived Electron Spin Qutrits in a Molecular Donor–Acceptor Single Cocrystal

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 146(1), P. 1089 - 1099

Published: Dec. 29, 2023

The photogeneration of multiple unpaired electron spins within molecules is a promising route to applications in quantum information science because they can be initialized into well-defined, multilevel states (S > 1/2) and reproducibly fabricated by chemical synthesis. However, coherent manipulation these spin difficult realize typical molecular systems due the lack selective addressability short coherence times transitions. Here, challenges are addressed using donor–acceptor single cocrystals composed pyrene naphthalene dianhydride host spatially oriented triplet excitons, which exhibit photogenerated qutrit properties. Time-resolved paramagnetic resonance (TREPR) spectroscopy demonstrates that orienting excitons crystal platform imparts narrow, well-resolved, tunable resonances EPR spectrum, allowing sublevel Pulse-EPR reveals at temperatures above 30 K, decoherence driven exciton diffusion. limited electronic dipolar coupling below where T2 varies nonlinearly with optical excitation density annihilation. Overall, an optimized time = 7.1 μs 20 K achieved. These results provide important insights designing solid-state excitonic materials improved

Language: Английский

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Singlet Fission in Terrylene Monoimide Single Crystals and Polycrystalline Films: Influence of an Intramolecular Charge Transfer State

The Journal of Physical Chemistry C, Journal Year: 2024, Volume and Issue: 128(1), P. 58 - 66

Published: Jan. 2, 2024

Singlet fission (SF) is a photophysical process in which high energy photon absorbed by one chromophore of an adjacent electronically coupled pair and converted into two lower-energy triplet excitons, resides on each chromophore. The SF rate efficiency are determined the gap between lowest excited singlet states chromophores electronic coupling them as controlled interchromophore geometry. Terrylene-3,4-dicarboximide (TMI) meets energetic requirements for but has yet to be studied. TMI particularly interesting, because its asymmetry results significant intramolecular charge transfer character. Here, we characterize photophysics solution, single crystals, polycrystalline films. absorption emission spectra strongly solvent dependent, indicating that dipole moment change ground 9.8 D. crystals films proceeds from state having CT character at τ = 12.8 16.3 ps, respectively, near quantitative yield. This work shows may play role promoting SF.

Language: Английский

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