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Zhu W, Wu Y, Zhang Y, Sukhanov AA, Chu Y, Zhang X, Zhao J, Voronkova VK. Preparation of Xanthene-TEMPO Dyads: Synthesis and Study of the Radical Enhanced Intersystem Crossing. Int J Mol Sci 2023; 24:11220. [PMID: 37446398 DOI: 10.3390/ijms241311220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 07/03/2023] [Accepted: 07/03/2023] [Indexed: 07/15/2023] Open
Abstract
We prepared a rhodamine-TEMPO chromophore-radical dyad (RB-TEMPO) to study the radical enhanced intersystem crossing (REISC). The visible light-harvesting chromophore rhodamine is connected with the TEMPO (a nitroxide radical) via a C-N bond. The UV-vis absorption spectrum indicates negligible electron interaction between the two units at the ground state. Interestingly, the fluorescence of the rhodamine moiety is strongly quenched in RB-TEMPO, and the fluorescence lifetime of the rhodamine moiety is shortened to 0.29 ns, from the lifetime of 3.17 ns. We attribute this quenching effect to the intramolecular electron spin-spin interaction between the nitroxide radical and the photoexcited rhodamine chromophore. Nanosecond transient absorption spectra confirm the REISC in RB-TEMPO, indicated by the detection of the rhodamine chromophore triplet excited state; the lifetime was determined as 128 ns, which is shorter than the native rhodamine triplet state lifetime (0.58 μs). The zero-field splitting (ZFS) parameters of the triplet state of the chromophore were determined with the pulsed laser excited time-resolved electron paramagnetic resonance (TREPR) spectra. RB-TEMPO was used as a photoinitiator for the photopolymerization of pentaerythritol triacrylate (PETA). These studies are useful for the design of heavy atom-free triplet photosensitizers, the study of the ISC, and the electron spin dynamics of the radical-chromophore systems upon photoexcitation.
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Affiliation(s)
- Wenhui Zhu
- State Key Laboratory of Fine Chemicals, Frontier Science Center for Smart Materials, School of Chemical Engineering, Dalian University of Technology, 2 Ling Gong Road, Dalian 116024, China
| | - Yanran Wu
- State Key Laboratory of Fine Chemicals, Frontier Science Center for Smart Materials, School of Chemical Engineering, Dalian University of Technology, 2 Ling Gong Road, Dalian 116024, China
| | - Yiyan Zhang
- State Key Laboratory of Fine Chemicals, Frontier Science Center for Smart Materials, School of Chemical Engineering, Dalian University of Technology, 2 Ling Gong Road, Dalian 116024, China
| | - Andrey A Sukhanov
- Zavoisky Physical-Technical Institute, FRC Kazan Scientific Center of Russian Academy of Sciences, Kazan 420029, Russia
| | - Yuqi Chu
- State Key Laboratory of Fine Chemicals, Frontier Science Center for Smart Materials, School of Chemical Engineering, Dalian University of Technology, 2 Ling Gong Road, Dalian 116024, China
| | - Xue Zhang
- State Key Laboratory of Fine Chemicals, Frontier Science Center for Smart Materials, School of Chemical Engineering, Dalian University of Technology, 2 Ling Gong Road, Dalian 116024, China
| | - Jianzhang Zhao
- State Key Laboratory of Fine Chemicals, Frontier Science Center for Smart Materials, School of Chemical Engineering, Dalian University of Technology, 2 Ling Gong Road, Dalian 116024, China
| | - Violeta K Voronkova
- Zavoisky Physical-Technical Institute, FRC Kazan Scientific Center of Russian Academy of Sciences, Kazan 420029, Russia
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2
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Nishimura K, Yabuki R, Hamachi T, Kimizuka N, Tateishi K, Uesaka T, Yanai N. Dynamic Electron Polarization Lasting More Than 10 μs by Hybridizing Porphyrin and TEMPO with Flexible Linkers. J Phys Chem B 2023; 127:1219-1228. [PMID: 36717096 DOI: 10.1021/acs.jpcb.2c07936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Dynamic electron polarization (DEP), induced by quenching of photoexcited species by stable radicals, can hyperpolarize electron spins in solution at room temperature. Recently, development of technologies based on electron spin polarization such as dynamic nuclear polarization (DNP) has been progressing, where it is important to design molecules that achieve long-lasting DEP in addition to high DEP. Hybridization by linking dyes and radicals is a promising approach for efficient DEP, but strong interactions between neighboring dyes and radicals often result in the rapid decay of DEP. In this study, we introduce a flexible linker into the hybrid system of porphyrin and TEMPO to achieve both efficient DEP and long-lasting DEP. The structural flexibility of the linker switches the interaction between the radical and the triplet, which promotes the DEP process by bringing the radical and the triplet into close proximity, while avoiding abrupt relaxation due to strong interactions. As a result, the new hybridized system exhibits a larger DEP than the unlinked system, while at the same time achieving a DEP lasting more than 10 μs.
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Affiliation(s)
- Koki Nishimura
- Department of Chemistry and Biochemistry, Graduate School of Engineering, Center for Molecular Systems (CMS), Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka819-0395, Japan
| | - Reiya Yabuki
- Department of Chemistry and Biochemistry, Graduate School of Engineering, Center for Molecular Systems (CMS), Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka819-0395, Japan
| | - Tomoyuki Hamachi
- Department of Chemistry and Biochemistry, Graduate School of Engineering, Center for Molecular Systems (CMS), Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka819-0395, Japan
| | - Nobuo Kimizuka
- Department of Chemistry and Biochemistry, Graduate School of Engineering, Center for Molecular Systems (CMS), Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka819-0395, Japan
| | - Kenichiro Tateishi
- Cluster for Pioneering Research, RIKEN, RIKEN Nishina Center for Accelerator-Based Science, 2-1 Hirosawa, Wako, Saitama351-0198, Japan
| | - Tomohiro Uesaka
- Cluster for Pioneering Research, RIKEN, RIKEN Nishina Center for Accelerator-Based Science, 2-1 Hirosawa, Wako, Saitama351-0198, Japan
| | - Nobuhiro Yanai
- Department of Chemistry and Biochemistry, Graduate School of Engineering, Center for Molecular Systems (CMS), Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka819-0395, Japan
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3
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Eills J, Budker D, Cavagnero S, Chekmenev EY, Elliott SJ, Jannin S, Lesage A, Matysik J, Meersmann T, Prisner T, Reimer JA, Yang H, Koptyug IV. Spin Hyperpolarization in Modern Magnetic Resonance. Chem Rev 2023; 123:1417-1551. [PMID: 36701528 PMCID: PMC9951229 DOI: 10.1021/acs.chemrev.2c00534] [Citation(s) in RCA: 55] [Impact Index Per Article: 55.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Magnetic resonance techniques are successfully utilized in a broad range of scientific disciplines and in various practical applications, with medical magnetic resonance imaging being the most widely known example. Currently, both fundamental and applied magnetic resonance are enjoying a major boost owing to the rapidly developing field of spin hyperpolarization. Hyperpolarization techniques are able to enhance signal intensities in magnetic resonance by several orders of magnitude, and thus to largely overcome its major disadvantage of relatively low sensitivity. This provides new impetus for existing applications of magnetic resonance and opens the gates to exciting new possibilities. In this review, we provide a unified picture of the many methods and techniques that fall under the umbrella term "hyperpolarization" but are currently seldom perceived as integral parts of the same field. Specifically, before delving into the individual techniques, we provide a detailed analysis of the underlying principles of spin hyperpolarization. We attempt to uncover and classify the origins of hyperpolarization, to establish its sources and the specific mechanisms that enable the flow of polarization from a source to the target spins. We then give a more detailed analysis of individual hyperpolarization techniques: the mechanisms by which they work, fundamental and technical requirements, characteristic applications, unresolved issues, and possible future directions. We are seeing a continuous growth of activity in the field of spin hyperpolarization, and we expect the field to flourish as new and improved hyperpolarization techniques are implemented. Some key areas for development are in prolonging polarization lifetimes, making hyperpolarization techniques more generally applicable to chemical/biological systems, reducing the technical and equipment requirements, and creating more efficient excitation and detection schemes. We hope this review will facilitate the sharing of knowledge between subfields within the broad topic of hyperpolarization, to help overcome existing challenges in magnetic resonance and enable novel applications.
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Affiliation(s)
- James Eills
- Institute
for Bioengineering of Catalonia, Barcelona
Institute of Science and Technology, 08028Barcelona, Spain,
| | - Dmitry Budker
- Johannes
Gutenberg-Universität Mainz, 55128Mainz, Germany,Helmholtz-Institut,
GSI Helmholtzzentrum für Schwerionenforschung, 55128Mainz, Germany,Department
of Physics, UC Berkeley, Berkeley, California94720, United States
| | - Silvia Cavagnero
- Department
of Chemistry, University of Wisconsin, Madison, Madison, Wisconsin53706, United States
| | - Eduard Y. Chekmenev
- Department
of Chemistry, Integrative Biosciences (IBio), Karmanos Cancer Institute
(KCI), Wayne State University, Detroit, Michigan48202, United States,Russian
Academy of Sciences, Moscow119991, Russia
| | - Stuart J. Elliott
- Molecular
Sciences Research Hub, Imperial College
London, LondonW12 0BZ, United Kingdom
| | - Sami Jannin
- Centre
de RMN à Hauts Champs de Lyon, Université
de Lyon, CNRS, ENS Lyon, Université Lyon 1, 69100Villeurbanne, France
| | - Anne Lesage
- Centre
de RMN à Hauts Champs de Lyon, Université
de Lyon, CNRS, ENS Lyon, Université Lyon 1, 69100Villeurbanne, France
| | - Jörg Matysik
- Institut
für Analytische Chemie, Universität
Leipzig, Linnéstr. 3, 04103Leipzig, Germany
| | - Thomas Meersmann
- Sir
Peter Mansfield Imaging Centre, University Park, School of Medicine, University of Nottingham, NottinghamNG7 2RD, United Kingdom
| | - Thomas Prisner
- Institute
of Physical and Theoretical Chemistry and Center of Biomolecular Magnetic
Resonance, Goethe University Frankfurt, , 60438Frankfurt
am Main, Germany
| | - Jeffrey A. Reimer
- Department
of Chemical and Biomolecular Engineering, UC Berkeley, and Materials Science Division, Lawrence Berkeley National
Laboratory, Berkeley, California94720, United States
| | - Hanming Yang
- Department
of Chemistry, University of Wisconsin, Madison, Madison, Wisconsin53706, United States
| | - Igor V. Koptyug
- International Tomography Center, Siberian
Branch of the Russian Academy
of Sciences, 630090Novosibirsk, Russia,
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4
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Cheney DJ, Wedge CJ. Sample volume effects in optical overhauser dynamic nuclear polarization. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2022; 337:107170. [PMID: 35240365 DOI: 10.1016/j.jmr.2022.107170] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Revised: 02/13/2022] [Accepted: 02/16/2022] [Indexed: 06/14/2023]
Abstract
The optical dynamic nuclear polarization (DNP) method has been proposed as an alternative to microwave pumping as a hyperpolarization method for solution-state NMR studies. Using continuous laser illumination to photogenerate triplet states in the presence of a persistent radical produces chemically-induced dynamic electron polarization (CIDEP) via the radical-triplet pair mechanism (RTPM), with cross-relaxation transferring this to nuclear hyperpolarization via an Overhauser mechanism. Numerical simulations have previously indicated that reducing the sample volume while maintaining a constant optical density can significantly increase the NMR signal enhancement, due to the larger steady-state concentration of triplets obtained. Here we provide the first experimental confirmation of these effects, producing a nearly five-fold increase in the optical DNP enhancement factor just by reducing the sample volume with optimal dye and radical concentrations adjusted for each optical path length. The results are supported with an in depth analysis of volume effects in the numerical model, with which they are in good qualitative agreement. These important observations will impact on the future development of the technique, with particular significance for attempts to apply DNP methods to increase sensitivity for volume-limited biological samples.
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Affiliation(s)
- Daniel J Cheney
- Department of Chemical Sciences, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, United Kingdom
| | - Christopher J Wedge
- Department of Chemical Sciences, University of Huddersfield, Queensgate, Huddersfield HD1 3DH, United Kingdom.
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5
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Rane V. Harnessing Electron Spin Hyperpolarization in Chromophore-Radical Spin Probes for Subcellular Resolution in Electron Paramagnetic Resonance Imaging: Concept and Feasibility. J Phys Chem B 2022; 126:2715-2728. [PMID: 35353514 DOI: 10.1021/acs.jpcb.1c10920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Obtaining a subcellular resolution for biological samples doped with stable radicals at room temperature (RT) is a long-sought goal in electron paramagnetic resonance imaging (EPRI). The spatial resolution in current EPRI methods is constrained either because of low electron spin polarization at RT or the experimental limitations associated with the field gradients and the radical linewidth. Inspired by the recent demonstration of a large electron spin hyperpolarization in chromophore-nitroxyl spin probe molecules, the present work proposes a novel optically hyperpolarized EPR imaging (OH-EPRI) method, which combines the optical method of two-photon confocal microscopy for hyperpolarization generation and the rapid scan (RS) EPR method for signal detection. An important aspect of OH-EPRI is that it is not limited by the abovementioned restrictions of conventional EPRI since the large hyperpolarization in the spin probes overcomes the poor thermal spin polarization at RT, and the use of two-photon optical excitation of the chromophore naturally generates the required spatial resolution, without the need for any magnetic field gradient. Simulations based on time-dependent Bloch equations, which took into account both the RS field modulation and the hyperpolarization generation by optical means, were performed to examine the feasibility of OH-EPRI. The simulation results revealed that a spatial resolution of up to 2 fL can be achieved in OH-EPRI at RT under in vitro conditions. Notably, the majority of the requirements for an OH-EPRI experiment can be fulfilled by the currently available technologies, thereby paving the way for its easy implementation. Thus, the proposed method could potentially bridge the sensitivity gap between the optical and magnetic imaging techniques.
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Affiliation(s)
- Vinayak Rane
- Radiochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India
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6
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Dale MW, Cheney DJ, Vallotto C, Wedge CJ. Viscosity effects on optically generated electron and nuclear spin hyperpolarization. Phys Chem Chem Phys 2020; 22:28173-28182. [PMID: 33291127 DOI: 10.1039/d0cp04012f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Spin hyperpolarization can dramatically increase signal intensities in magnetic resonance experiments, providing either improved bulk sensitivity or additional spectroscopic detail through selective enhancements. While typical hyperpolarization approaches have utilized microwave irradiation, one emerging route is the use of optically generated triplet states. We report an investigation into the effects of solution viscosity on radical-triplet pair interactions, propose a new standard for quantification of the hyperpolarization in EPR experiments, and demonstrate a significant increase in the optically generated 1H NMR signal enhancement upon addition of glycerol to aqueous solutions.
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Affiliation(s)
- Matthew W Dale
- Department of Physics, University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL, UK
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7
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Cheney DJ, Wedge CJ. Optically-generated Overhauser dynamic nuclear polarization: A numerical analysis. J Chem Phys 2020; 152:034202. [DOI: 10.1063/1.5133408] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Daniel J. Cheney
- Department of Chemical Sciences, University of Huddersfield, Queensgate, Huddersfield, United Kingdom
| | - Christopher J. Wedge
- Department of Chemical Sciences, University of Huddersfield, Queensgate, Huddersfield, United Kingdom
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8
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Tripathi A, Rane V. Toward Achieving the Theoretical Limit of Electron Spin Polarization in Covalently Linked Radical-Chromophore Dyads. J Phys Chem B 2019; 123:6830-6841. [DOI: 10.1021/acs.jpcb.9b04726] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Alok Tripathi
- Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005, India
| | - Vinayak Rane
- Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India
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9
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Serrer K, Matt C, Sokolov M, Kacprzak S, Schleicher E, Weber S. Application of commercially available fluorophores as triplet spin probes in EPR spectroscopy. Mol Phys 2019. [DOI: 10.1080/00268976.2019.1608379] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Kerstin Serrer
- Institute of Physical Chemistry, University of Freiburg, Freiburg, Germany
| | - Clemens Matt
- Institute of Physical Chemistry, University of Freiburg, Freiburg, Germany
| | - Monja Sokolov
- Institute of Physical Chemistry, University of Freiburg, Freiburg, Germany
| | - Sylwia Kacprzak
- Institute of Physical Chemistry, University of Freiburg, Freiburg, Germany
| | - Erik Schleicher
- Institute of Physical Chemistry, University of Freiburg, Freiburg, Germany
| | - Stefan Weber
- Institute of Physical Chemistry, University of Freiburg, Freiburg, Germany
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10
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Liu G, Liou SH, Enkin N, Tkach I, Bennati M. Photo-induced radical polarization and liquid-state dynamic nuclear polarization using fullerene nitroxide derivatives. Phys Chem Chem Phys 2017; 19:31823-31829. [DOI: 10.1039/c7cp06073d] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Continuous wave laser irradiation of fullerene–nitroxide derivatives at room temperature leads to spin polarization and NMR signal enhancement of toluene solvent protons.
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Affiliation(s)
- Guoquan Liu
- RG EPR Spectroscopy
- Max Planck Institute for Biophysical Chemistry
- 37077 Göttingen
- Germany
| | - Shu-Hao Liou
- RG EPR Spectroscopy
- Max Planck Institute for Biophysical Chemistry
- 37077 Göttingen
- Germany
| | - Nikolay Enkin
- RG EPR Spectroscopy
- Max Planck Institute for Biophysical Chemistry
- 37077 Göttingen
- Germany
| | - Igor Tkach
- RG EPR Spectroscopy
- Max Planck Institute for Biophysical Chemistry
- 37077 Göttingen
- Germany
| | - Marina Bennati
- RG EPR Spectroscopy
- Max Planck Institute for Biophysical Chemistry
- 37077 Göttingen
- Germany
- Department of Chemistry
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11
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Shushin AI, Sakun VP. Characteristic features of the singlet–triplet mechanism of the electron spin polarization. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY B 2016. [DOI: 10.1134/s1990793116020093] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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12
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Dale MW, Wedge CJ. Optically generated hyperpolarization for sensitivity enhancement in solution-state NMR spectroscopy. Chem Commun (Camb) 2016; 52:13221-13224. [DOI: 10.1039/c6cc06651h] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Using optical excitation to generate radical triplet pairs the sensitivity of solution-state NMR can be enhanced without microwave pumping.
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13
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Shushin AI. Radical-triplet pair mechanism of electron spin polarization. Detailed theoretical treatment. J Phys Chem A 2014; 118:11355-63. [PMID: 25383486 DOI: 10.1021/jp509199m] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Specific features of net chemically induced dynamic electron spin polarization (CIDEP) P(n), generated in liquid-phase triplet-radical (TR) quenching, are analyzed in detail within the general model, which allows for fairly simple analysis of CIDEP both numerically and analytically. This model enables one to accurately treat nonadiabatic transitions between the terms of TR-pair spin Hamiltonian, resulting in CIDEP generation. The proposed theory predicts fairly simple analytical dependence of P(n) on parameters of the model. In particular, it is shown that within the wide region of parameters the P(n) dependence on the coefficient of relative TR diffusion D(r) is described by simple linear relation P(n)(-1)(D(r)) ≈ Q0 + q̅(n)D(r) (Q0 and q̅(n) are independent of D(r)). It is also demonstrated that obtained numerical and analytical results are very helpful for the analysis of experimental data, which is demonstrated by analyzing the experimental D(r)-dependence of P(n).
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Affiliation(s)
- A I Shushin
- Institute of Chemical Physics, Russian Academy of Sciences , GSP-1, Kosygin Street 4, 117977 Moscow, Russia
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14
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Jeschke G. Topical review introduction. Mol Phys 2014. [DOI: 10.1080/00268976.2014.930989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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