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

Journal of Magnetic Resonance, Год журнала: 2023, Номер 349, С. 107410 - 107410

Опубликована: Фев. 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.

Язык: Английский

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Entangled spin-polarized excitons from singlet fission in a rigid dimer

Nature Communications, Год журнала: 2023, Номер 14(1)

Опубликована: Март 2, 2023

Singlet fission, a process that splits singlet exciton into biexciton, has promise in quantum information. We report time-resolved electron paramagnetic resonance measurements on conformationally well-defined acene dimer molecule, TIPS-BP1', designed to exhibit strongly state-selective relaxation specific magnetic spin sublevels. The resulting optically pumped polarization is nearly pure initial state from the ensemble. long-lived coherences modulate signal intrinsically, allowing measurement scheme substantially removes noise and uncertainty spectra. A nonadiabatic transition theory with minimal number of spectroscopic parameters allows quantitative assignment interpretation In this work, we show rigid TIPS-BP1' supports persistent at temperatures far higher than those used conventional superconducting hardware.

Язык: Английский

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Singlet fission as a polarized spin generator for dynamic nuclear polarization

Nature Communications, Год журнала: 2023, Номер 14(1)

Опубликована: Март 1, 2023

Singlet fission (SF), converting a singlet excited state into spin-correlated triplet-pair state, is an effective way to generate spin quintet in organic materials. Although its application photovoltaics as exciton multiplier has been extensively studied, the use of unique degree freedom largely unexplored. Here, we demonstrate that polarization multiexcitons generated by SF improves sensitivity magnetic resonance water molecules through dynamic nuclear (DNP). We form supramolecular assemblies few pentacene chromophores and SF-born spins achieve DNP water-glycerol, most basic biological matrix, evidenced dependence enhancement on field microwave power. Our demonstration opens polarized generator bio-quantum technology.

Язык: Английский

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A framework for multiexcitonic logic

Nature Reviews Chemistry, Год журнала: 2024, Номер 8(2), С. 136 - 151

Опубликована: Янв. 25, 2024

Язык: Английский

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Room-temperature quantum coherence of entangled multiexcitons in a metal-organic framework

Science Advances, Год журнала: 2024, Номер 10(1)

Опубликована: Янв. 3, 2024

Singlet fission can generate an exchange-coupled quintet triplet pair state

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Aromaticity Tuning of Heavy-Atom-Free Photosensitizers for Singlet Fission-Enhanced Immunogenic Photodynamic Oncotherapy

Nano Letters, Год журнала: 2024, Номер 24(24), С. 7524 - 7533

Опубликована: Июнь 10, 2024

The quantum yield of reactive oxygen species is central importance for the development organic photosensitizers and photodynamic therapy (PDT). A common molecular design approach optimizing involves incorporation heavy atoms into their backbones. However, this raises concerns regarding heightened dark cytotoxicity a shortened triplet-state lifetime. Herein, we demonstrate heavy-atom-free (HAF) photosensitizer strategy founded on singlet fission (SF) mechanism cancer PDT. Through "single-atom surgery" to deleting in pyrazino[2,3-

Язык: Английский

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Electronic Spin Qubit Candidates Arrayed within Layered Two-Dimensional Polymers

Journal of the American Chemical Society, Год журнала: 2022, Номер 145(1), С. 689 - 696

Опубликована: Дек. 27, 2022

Molecular electronic spin qubits are promising candidates for quantum information science applications because they can be reliably produced and engineered via chemical design. Embedding within two-dimensional polymers (2DPs) offers the possibility to systematically engineer inter-qubit interactions while maintaining long coherence times, both of which prerequisites their technological utility. Here, we introduce into a diamagnetic 2DP by n-doping naphthalene diimide subunits with varying amounts CoCp2 analyze densities quantitative paramagnetic resonance spectroscopy. Low (e.g., 6.0 × 1012 spins mm-3) enable lengthy spin-lattice (T1) spin-spin relaxation (T2) times across range temperatures, ranging from T1 values 164 ms at 10 K 30.2 μs 296 T2 2.36 0.49 lowest density sample examined. Higher temperatures were found diminish attribute detrimental cross-relaxation dipolar spin-phonon coupling, respectively. decreased modulated temperature dependence. We these differences competition between hyperfine electron decoherence, dominant interaction transitioning former latter as increase. Overall, this investigation demonstrates that dispersing layered 2DPs enables control decoherence times.

Язык: Английский

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Controlling Intramolecular Singlet Fission Dynamics via Torsional Modulation of Through-Bond versus Through-Space Couplings

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(38), С. 20883 - 20896

Опубликована: Сен. 14, 2023

Covalent dimers, particularly pentacenes, are the dominant platform for developing a mechanistic understanding of intramolecular singlet fission (iSF). Numerous studies have demonstrated that photoexcited state in these structures can rapidly and efficiently undergo exciton multiplication to form correlated pair triplets within single molecule, with potential applications from photovoltaics quantum information science. One most significant barriers limiting such dimers is fast recombination triplet pair, which prevents spatial separation formation long-lived states. There an ever-growing need develop general synthetic strategies control evolution following iSF enhance their lifetime. Here, we rationally tune dihedral angle interchromophore between pairs pentacenes systematic series bridging units facilitate separation. Through combination transient optical spin-resonance techniques, demonstrate torsion linker provides simple handle fine balance through-bond through-space couplings steer iSF. We show full pathway femtosecond microsecond timescales tuned through static coupling set by molecular design structural fluctuations be biased steric control. Our approach highlights straightforward principle generate paramagnetic spin states higher yields.

Язык: Английский

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Effect of halogenation on the photophysics of salicylideneimine-boron compound: An unusual behaviour with bromination

Journal of Photochemistry and Photobiology A Chemistry, Год журнала: 2025, Номер unknown, С. 116361 - 116361

Опубликована: Фев. 1, 2025

Язык: Английский

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Triplet-pair spin signatures from macroscopically aligned heteroacenes in an oriented single crystal

Proceedings of the National Academy of Sciences, Год журнала: 2022, Номер 119(29)

Опубликована: Июль 13, 2022

The photo-driven process of singlet fission generates coupled triplet pairs (TT) with fundamentally intriguing and potentially useful properties. quintet 5 TT 0 sublevel is particularly interesting for quantum information because it highly entangled, addressable microwave pulses, could be detected using optical techniques. Previous theoretical work on a model Hamiltonian nonadiabatic transition theory, called the JDE model, has determined that this can selectively populated if certain conditions are met. Among most challenging, molecules within dimer undergoing must have their principal magnetic axes parallel to one another an applied Zeeman field. Here, we present time-resolved electron paramagnetic resonance (TR-EPR) spectroscopy single crystal sample tetracenethiophene compound featuring arrays dimers aligned in manner, which were mounted so orientation field relative molecular controlled. observed spin populations paired unpaired (T+T) triplets consistent predictions from including preferential formation at z ‖ B , caveat—two sublevels little no population. This may due crossings between 3 manifolds range investigated by TR-EPR, intertriplet exchange energy monitoring photoluminescence varying fields.

Язык: Английский

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