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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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Lin S, Peng Y, Hu J, Wang J, Li Y, Song G. Development and Application of a Microwave Reactor Radiating through a Leaky Coaxial Antenna. Chem Eng Technol 2017. [DOI: 10.1002/ceat.201600289] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Shengjie Lin
- East China University of Science and Technology; Shanghai Key Laboratory of Chemical Biology; School of Pharmacy; 130 Meilong Road 200237 Shanghai China
| | - Yanqing Peng
- East China University of Science and Technology; Shanghai Key Laboratory of Chemical Biology; School of Pharmacy; 130 Meilong Road 200237 Shanghai China
| | - Junjie Hu
- East China University of Science and Technology; Shanghai Key Laboratory of Chemical Biology; School of Pharmacy; 130 Meilong Road 200237 Shanghai China
| | - Jiayi Wang
- East China University of Science and Technology; Shanghai Key Laboratory of Chemical Biology; School of Pharmacy; 130 Meilong Road 200237 Shanghai China
| | - Yu Li
- East China University of Science and Technology; School of Information Science and Engineering; 130 Meilong Road 200237 Shanghai China
| | - Gonghua Song
- East China University of Science and Technology; Shanghai Key Laboratory of Chemical Biology; School of Pharmacy; 130 Meilong Road 200237 Shanghai China
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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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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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Takahashi H, Iwama M, Akai N, Shibuya K, Kawai A. Pulsed EPR study on large dynamic electron polarisation created in the quenching of photo-excited xanthene dyes by nitroxide radicals in aqueous solutions. Mol Phys 2013. [DOI: 10.1080/00268976.2013.827255] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Moons H, Goovaerts E, Gubskaya VP, Nuretdinov IA, Corvaja C, Franco L. W-band transient EPR and photoinduced absorption on spin-labeled fullerene derivatives. Phys Chem Chem Phys 2011; 13:3942-51. [DOI: 10.1039/c0cp01902j] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Colton JS, Wienkes LR. Resonant microwave cavity for 8.5-12 GHz optically detected electron spin resonance with simultaneous nuclear magnetic resonance. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2009; 80:035106. [PMID: 19334951 DOI: 10.1063/1.3095683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We present a newly developed microwave resonant cavity for use in optically detected magnetic resonance (ODMR) experiments. The cylindrical quasi-TE(011) mode cavity is designed to fit in a 1 in. magnet bore to allow the sample to be optically accessed and to have an adjustable resonant frequency between 8.5 and 12 GHz. The cavity uses cylinders of high dielectric material, so-called "dielectric resonators," in a double-stacked configuration to determine the resonant frequency. Wires in a pseudo-Helmholtz configuration are incorporated into the cavity to provide frequencies for simultaneous nuclear magnetic resonance (NMR). The system was tested by measuring cavity absorption as microwave frequencies were swept, by performing ODMR on a zinc-doped InP sample, and by performing optically detected NMR on a GaAs sample. The results confirm the suitability of the cavity for ODMR with simultaneous NMR.
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Affiliation(s)
- J S Colton
- Department of Physics and Astronomy, Brigham Young University, Provo Utah 84602, USA.
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Kawai A, Shibuya K. Charge-Transfer Controlled Exchange Interaction in Radical-Triplet Encounter Pairs as Studied by FT-EPR Spectroscopy. J Phys Chem A 2007; 111:4890-901. [PMID: 17518447 DOI: 10.1021/jp067753d] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The exchange interaction, J, producing quartet and doublet energy separation in radical-triplet excited molecule encounter pairs, was investigated in solution by measuring chemically induced dynamic electron polarization (CIDEP) created through the radical-triplet pair mechanism. A time-resolved FT-EPR method was utilized to measure CIDEP of galvinoxyl radical by recording FID signals and an absolute magnitude of CIDEP, P(n), was determined for each radical-triplet system by detailed analysis of the time evolution curves of CIDEP. A transient FT-EPR signal phase remarkably depends on the triplet molecule. The signal phase is related to the sign of J value, which is responsible for the radical-triplet pair interaction. Most of galvinoxyl-triplet systems showed normal negative sign. An unusual positive sign was found in some systems characterized by a small energy gap, DeltaG, between the radical-triplet pair and intermolecular charge transfer (CT) states. A theoretical calculation of J value for radical-triplet encounter pairs was carried out by considering exchange integral and intermolecular CT interaction. According to the calculated J value and the diffusion theory for CIDEP magnitude, experimental Pn values were theoretically reproduced as a function of DeltaG. The present results confirm our previously reported CT model explaining the complicated nature of the sign of J value in the galvinoxyl-triplet encounter pairs. According to the proposed model for CT effect on J value and CIDEP results, nature of J value in radical-triplet pairs is discussed.
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Affiliation(s)
- Akio Kawai
- Department of Chemistry, Graduate School of Science and Engineering, Tokyo Institute of Technology, 2-12-1 Ohokayama, Tokyo 152-8551, Japan.
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Bagryanskaya E, Fedin M, Forbes MDE. CIDEP of Micellized Radical Pairs in Low Magnetic Fields. J Phys Chem A 2005; 109:5064-9. [PMID: 16833859 DOI: 10.1021/jp050499p] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We report the first experimental study of chemically induced electron spin polarization (CIDEP) processes in low magnetic fields for spin-correlated radical pairs (SCRPs) in micellar environments. Photoexcitation of (2,4,6-trimethylbenzoyl) diphenylphosphine oxide (TMBDPO) leads to the radical pair comprised of acyl radical 1 and phosphonyl radical 2. The spin polarization, which is very strong in free solution even at zero field, was detected using L-band time-resolved electron paramagnetic resonance (TREPR) spectroscopy with specially modified resonators. The mechanism of formation and decay of low field CIDEP in SCRPs is presented and discussed. The prominent difference between low and high field spectra in micelles is the absence of anti-phase structure for radical 2 with HFI a > B0. This feature is consistent with the proposed polarization mechanism and theoretical predictions.
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Affiliation(s)
- Elena Bagryanskaya
- International Tomography Center, Siberian Branch, Russian Academy of Sciences, Novosibirsk 630090, Russia.
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