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Geometrization for Energy Levels of Isotropic Hyperfine Hamiltonian Block and Related Central Spin Problems for an Arbitrarily Complex Set of Spin-1/2 Nuclei. Int J Mol Sci 2022; 23:ijms232315199. [PMID: 36499535 PMCID: PMC9739289 DOI: 10.3390/ijms232315199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 11/20/2022] [Accepted: 11/29/2022] [Indexed: 12/12/2022] Open
Abstract
Description of interacting spin systems relies on understanding the spectral properties of the corresponding spin Hamiltonians. However, the eigenvalue problems arising here lead to algebraic problems too complex to be analytically tractable. This is already the case for the simplest nontrivial (Kmax−1) block for an isotropic hyperfine Hamiltonian for a radical with spin-12 nuclei, where n nuclei produce an n-th order algebraic equation with n independent parameters. Systems described by such blocks are now physically realizable, e.g., as radicals or radical pairs with polarized nuclear spins, appear as closed subensembles in more general radical settings, and have numerous counterparts in related central spin problems. We provide a simple geometrization of energy levels in this case: given n spin-12 nuclei with arbitrary positive couplings ai, take an n-dimensional hyper-ellipsoid with semiaxes ai, stretch it by a factor of n+1 along the spatial diagonal (1, 1, …, 1), read off the semiaxes of thus produced new hyper-ellipsoid qi, augment the set {qi} with q0=0, and obtain the sought n+1 energies as Ek=−12qk2+14∑iai. This procedure provides a way of seeing things that can only be solved numerically, giving a useful tool to gain insights that complement the numeric simulations usually inevitable here, and shows an intriguing connection to discrete Fourier transform and spectral properties of standard graphs.
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Ochiai H, Miura T, Ikoma T, Minoura M, Nakano H, Matano Y. Copper(II) Complexes of 10,20-Diaryl-5,15-diazaporphyrin: Alternative Synthesis, Excited State Dynamics, and Substituent Effect on the 1O2-Generation Efficiency. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2022. [DOI: 10.1246/bcsj.20220002] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Hikari Ochiai
- Department of Fundamental Sciences, Graduate School of Science and Technology, Niigata University, Nishi-ku, Niigata 950-2181
| | - Tomoaki Miura
- Department of Chemistry, Faculty of Science, Niigata University, Nishi-ku, Niigata 950-2181
| | - Tadaaki Ikoma
- Department of Chemistry, Faculty of Science, Niigata University, Nishi-ku, Niigata 950-2181
| | - Mao Minoura
- Department of Chemistry, College of Science, Rikkyo University, Toshima-ku, Tokyo 171-8501
| | - Haruyuki Nakano
- Department of Chemistry, Graduate School of Science, Kyushu University, Nishi-ku, Fukuoka 819-0395
| | - Yoshihiro Matano
- Department of Chemistry, Faculty of Science, Niigata University, Nishi-ku, Niigata 950-2181
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Oka Y, Miura T, Ikoma T. Photogenerated Radical Pair between Flavin and a Tryptophan-Containing Transmembrane-Type Peptide in a Large Unilamellar Vesicle. J Phys Chem B 2021; 125:4057-4066. [PMID: 33858138 DOI: 10.1021/acs.jpcb.1c01231] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Electron-transfer (ET) reactions in biological systems, such as those with magnetic sensors based on flavoproteins and electron transport at biomembrane interfaces, are interesting and important issues that require understanding. As a model system of flavoproteins in biomimetic environments, we report the dynamics of the radical pair generated by photoinduced ET between riboflavin tetrabutylate (RFTB) and tryptophan (Trp) residues in a transmembrane-type polypeptide, both of which are distributed in a large unilamellar vesicle of 1,2-dimyristoyl-sn-glycero-3-phosphocholine. The Trp residues locate near the hydrophilic membrane interface, as confirmed by a dual-fluorescence quenching assay. The fluorescence and transient absorption upon photoexcitation of RFTB indicate that ET from both the singlet and triplet excited states occurs at the hydrophilic interface, whereas the RFTB in the hydrophobic region does not contribute to ET. The ET efficiency and the magnetic field effect (MFE) on the RFTB anion increase significantly above the gel-to-liquid crystal phase transition temperature due to a decrease in microviscosity. The MFE analysis indicates that the radical pair generated from the triplet ET channel exhibits a long lifetime as those in micellar systems due to the strong cage effect of the vesicle.
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Affiliation(s)
- Yoshimi Oka
- Frontier Research Core for Life Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan
| | - Tomoaki Miura
- Department of Chemistry, Faculty of Science, Niigata University, 2-8050 Ikarashi, Nishi-ku, Niigata 950-2181, Japan
| | - Tadaaki Ikoma
- Department of Chemistry, Faculty of Science, Niigata University, 2-8050 Ikarashi, Nishi-ku, Niigata 950-2181, Japan
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Hu JX, Jiang XF, Ma YJ, Liu XR, Ge BD, Wang AN, Wei Q, Wang GM. Optically actuating ultra-stable radicals in a large π-conjugated ligand constructed photochromic complex. Sci China Chem 2021. [DOI: 10.1007/s11426-020-9891-4] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Riese S, Brand JS, Mims D, Holzapfel M, Lukzen NN, Steiner UE, Lambert C. Giant magnetic field effects in donor–acceptor triads: On the charge separation and recombination dynamics in triarylamine–naphthalenediimide triads with bis-diyprrinato-palladium(II), porphodimethenato-palladium(II), and palladium(II)–porphyrin photosensitizers. J Chem Phys 2020; 153:054306. [DOI: 10.1063/5.0013941] [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)
- Stefan Riese
- Institute of Organic Chemistry, Center for Nanosystems Chemistry, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Jessica S. Brand
- Institute of Organic Chemistry, Center for Nanosystems Chemistry, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - David Mims
- Institute of Organic Chemistry, Center for Nanosystems Chemistry, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Marco Holzapfel
- Institute of Organic Chemistry, Center for Nanosystems Chemistry, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Nikita N. Lukzen
- International Tomography Center, Institutskaya 3a, Novosibirsk 630090, Russia and Novosibirsk State University, Novosibirsk 630090, Russia
| | - Ulrich E. Steiner
- Department of Chemistry, University of Konstanz, Universitätsstraße 14, 78457 Konstanz, Germany
| | - Christoph Lambert
- Institute of Organic Chemistry, Center for Nanosystems Chemistry, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
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Omomo S, Fukuda R, Miura T, Murakami T, Ikoma T, Matano Y. Effects of the Peripheral Substituents, Central Metal, and Solvent on the Photochemical and Photophysical Properties of 5,15-Diazaporphyrins. Chempluschem 2020; 84:740-745. [PMID: 31944027 DOI: 10.1002/cplu.201900087] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 02/13/2019] [Indexed: 12/23/2022]
Abstract
Metal complexes of 3,7,13,17-tetrakis(di(4-carboxyphenyl)amino)-5,15-diazaporphyrin (MDAP-COOH; M=Pd, Cu) and their ethyl ester precursors (MDAP-COOEt; M=Pd, Cu) have been synthesized for use as near-infrared (NIR)-light-responsive photosensitizers. Under irradiation with visible or NIR light, PdDAP-COOEt in toluene generated singlet oxygen (1 O2 ) with an excellent quantum yield (ΦΔ =0.99), whereas CuDAP-COOEt exhibited a lower efficiency (ΦΔ =0.21). The water-soluble PdII complex PdDAP-COOH also behaved as a photosensitizer (ΦΔ =0.20) in a micellar solution. The photophysical properties of these dyes were measured by transient absorption techniques. It was found that the efficiency of the energy transfer from the triplet state of MDAP-COOR (R=Et, H) to the ground state of dioxygen was highly dependent on the peripheral substituents, the central metal, and the solvent. Furthermore, the phototoxicity of PdDAP-COOH toward HeLa cells under irradiation of NIR light (720 nm) was evaluated. As expected, PdDAP-COOH exhibited good photodynamic activity, and control experiments confirmed that 1 O2 was generated as the active oxygen species.
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Affiliation(s)
- Satoshi Omomo
- Department of Fundamental Sciences Graduate School of Science and Technology, Niigata University, Nishi-ku, Niigata, 950-2181, Japan
| | - Ryosuke Fukuda
- Department of Biotechnology Graduate School of Engineering, Toyama Prefectural University, Imizu-shi, Toyama, 939-0398, Japan
| | - Tomoaki Miura
- Department of Chemistry Faculty of Science, Niigata University, Nishi-ku, Niigata, 950-2181, Japan
| | - Tatsuya Murakami
- Department of Biotechnology Graduate School of Engineering, Toyama Prefectural University, Imizu-shi, Toyama, 939-0398, Japan.,Institute for Integrated Cell-Material Sciences (iCeMS), Kyoto University Institute for Advanced Study (KUIAS), Sakyo-ku, Kyoto, 606-8501, Japan
| | - Tadaaki Ikoma
- Department of Chemistry Faculty of Science, Niigata University, Nishi-ku, Niigata, 950-2181, Japan.,Center for Coordination of Research Facilities, Niigata University, Nishi-ku, Niigata, 950-2181, Japan
| | - Yoshihiro Matano
- Department of Chemistry Faculty of Science, Niigata University, Nishi-ku, Niigata, 950-2181, Japan
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Miura T, Miyaji K, Horikoshi T, Suzuki S, Kozaki M, Okada K, Ikoma T. Spin-dependent electron transfer dynamics in a platinum-complex-donor-acceptor triad studied by transient-absorption detected magnetic field effect. J Chem Phys 2019; 151:234306. [PMID: 31864281 DOI: 10.1063/1.5127940] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
For realization of efficient organic light-energy conversion systems, controlling the lifetime of photogenerated charge separated states in donor (D)-acceptor (A) molecules is of much importance; the spin dynamics is one of the important controlling factors. We previously reported that the covalently-linked 1,3-bis(2-pyridylimino)-isoindolate platinum (BPIPt)-dimethoxytriphenylamine (D)-naphthaldiimide (A) triad molecule (BPIPt-DA) exhibits a triplet-born long-lived charge separated state (BPIPt-D•+A•-), the lifetime of which is significantly increased from 4 µs to 10 µs by an applied magnetic field of 270 mT in room temperature tetrahydrofuran (THF). The purpose of the present study is to clarify detailed dynamics of spin-dependent generation and the decay of BPIPt-D+A-. For this purpose, we measured transient optical absorption (TA) and the TA-detected magnetic field effect (MFE) as functions of temperature and dispersion media. In THF at 183 K, MFE-detected transient spectra of the intermediate BPIPt•--D•+A state are observed. We have successfully quantified the recombination loss at this state by a kinetic simulation of MFE without using any reference molecules. The lifetime of the final BPIPt-D•+A•- state in a cellulose acetate polymer matrix at room temperature is significantly prolonged to 20 µs at 0 mT and 96 µs at 250 mT compared to those in THF. From the comparison of temperature dependences of the two media, effects of molecular motions on the electronic coupling and the spin relaxation are discussed.
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Affiliation(s)
- Tomoaki Miura
- Department of Science, Niigata University, 2-8050 Ikarashi, Nishi-ku, Niigata 950-2181, Japan
| | - Kio Miyaji
- Department of Science, Niigata University, 2-8050 Ikarashi, Nishi-ku, Niigata 950-2181, Japan
| | - Takafumi Horikoshi
- Department of Chemistry, Graduate School of Science, Osaka City University, Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan
| | - Shuichi Suzuki
- Department of Chemistry, Graduate School of Science, Osaka City University, Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan
| | - Masatoshi Kozaki
- Department of Chemistry, Graduate School of Science, Osaka City University, Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan
| | - Keiji Okada
- Department of Chemistry, Graduate School of Science, Osaka City University, Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan
| | - Tadaaki Ikoma
- Department of Science, Niigata University, 2-8050 Ikarashi, Nishi-ku, Niigata 950-2181, Japan
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Miura T. Studies on coherent and incoherent spin dynamics that control the magnetic field effect on photogenerated radical pairs. Mol Phys 2019. [DOI: 10.1080/00268976.2019.1643510] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Tomoaki Miura
- Department of Science, Niigata University, Niigata, Japan
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