Magnetic Field Effect in Bimolecular Rate Constant of Radical Recombination
The influence of magnetic fields on chemical reactions, including biological ones, has been and still is a topical subject in the field of scientific research. Experimentally discovered and theoretically substantiated magnetic and spin effects in chemical radical reactions form the basis of research...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-04-01
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| Series: | International Journal of Molecular Sciences |
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| Online Access: | https://www.mdpi.com/1422-0067/24/8/7555 |
| _version_ | 1797605034274324480 |
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| author | Alexander B. Doktorov Nikita N. Lukzen |
| author_facet | Alexander B. Doktorov Nikita N. Lukzen |
| author_sort | Alexander B. Doktorov |
| collection | DOAJ |
| description | The influence of magnetic fields on chemical reactions, including biological ones, has been and still is a topical subject in the field of scientific research. Experimentally discovered and theoretically substantiated magnetic and spin effects in chemical radical reactions form the basis of research in the field of spin chemistry. In the present work, the effect of a magnetic field on the rate constant of the bimolecular spin-selective recombination of radicals in the bulk of a solution is considered theoretically for the first time, taking into account the hyperfine interaction of radical spins with their magnetic nuclei. In addition, the paramagnetic relaxation of unpaired spins of the radicals and the non-equality of their g-factors that also influence the recombination process are taken into account. It is found that the reaction rate constant can vary in magnetic field from a few to half a dozen percent, depending on the relative diffusion coefficient of radicals, which is determined by the solution viscosity. It is shown that the consideration of hyperfine interactions gives rise to the presence of resonances in the dependence of the rate constant on the magnetic field. The magnitudes of the magnetic fields of these resonances are determined by the hyperfine coupling constants and difference in the g-factors of the recombining radicals. Analytical expressions for the reaction rate constant of the bulk recombination for magnetic fields larger than hfi (hyperfine interaction) constants are obtained. In general, it is shown for the first time that accounting for hyperfine interactions of radical spins with magnetic nuclei significantly affects the dependence of the reaction rate constant of the bulk radical recombination on the magnetic field. |
| first_indexed | 2024-03-11T04:55:24Z |
| format | Article |
| id | doaj.art-b0c701e705c64f1d89de08af0c70d844 |
| institution | Directory Open Access Journal |
| issn | 1661-6596 1422-0067 |
| language | English |
| last_indexed | 2024-03-11T04:55:24Z |
| publishDate | 2023-04-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | International Journal of Molecular Sciences |
| spelling | doaj.art-b0c701e705c64f1d89de08af0c70d8442023-11-17T19:42:16ZengMDPI AGInternational Journal of Molecular Sciences1661-65961422-00672023-04-01248755510.3390/ijms24087555Magnetic Field Effect in Bimolecular Rate Constant of Radical RecombinationAlexander B. Doktorov0Nikita N. Lukzen1International Tomography Center SB RAS, 630090 Novosibirsk, RussiaInternational Tomography Center SB RAS, 630090 Novosibirsk, RussiaThe influence of magnetic fields on chemical reactions, including biological ones, has been and still is a topical subject in the field of scientific research. Experimentally discovered and theoretically substantiated magnetic and spin effects in chemical radical reactions form the basis of research in the field of spin chemistry. In the present work, the effect of a magnetic field on the rate constant of the bimolecular spin-selective recombination of radicals in the bulk of a solution is considered theoretically for the first time, taking into account the hyperfine interaction of radical spins with their magnetic nuclei. In addition, the paramagnetic relaxation of unpaired spins of the radicals and the non-equality of their g-factors that also influence the recombination process are taken into account. It is found that the reaction rate constant can vary in magnetic field from a few to half a dozen percent, depending on the relative diffusion coefficient of radicals, which is determined by the solution viscosity. It is shown that the consideration of hyperfine interactions gives rise to the presence of resonances in the dependence of the rate constant on the magnetic field. The magnitudes of the magnetic fields of these resonances are determined by the hyperfine coupling constants and difference in the g-factors of the recombining radicals. Analytical expressions for the reaction rate constant of the bulk recombination for magnetic fields larger than hfi (hyperfine interaction) constants are obtained. In general, it is shown for the first time that accounting for hyperfine interactions of radical spins with magnetic nuclei significantly affects the dependence of the reaction rate constant of the bulk radical recombination on the magnetic field.https://www.mdpi.com/1422-0067/24/8/7555radicalsspin-selective radical recombinationmagnetic and spin effects in chemical reactionsdiffusion-influenced reactionsspin chemistry |
| spellingShingle | Alexander B. Doktorov Nikita N. Lukzen Magnetic Field Effect in Bimolecular Rate Constant of Radical Recombination International Journal of Molecular Sciences radicals spin-selective radical recombination magnetic and spin effects in chemical reactions diffusion-influenced reactions spin chemistry |
| title | Magnetic Field Effect in Bimolecular Rate Constant of Radical Recombination |
| title_full | Magnetic Field Effect in Bimolecular Rate Constant of Radical Recombination |
| title_fullStr | Magnetic Field Effect in Bimolecular Rate Constant of Radical Recombination |
| title_full_unstemmed | Magnetic Field Effect in Bimolecular Rate Constant of Radical Recombination |
| title_short | Magnetic Field Effect in Bimolecular Rate Constant of Radical Recombination |
| title_sort | magnetic field effect in bimolecular rate constant of radical recombination |
| topic | radicals spin-selective radical recombination magnetic and spin effects in chemical reactions diffusion-influenced reactions spin chemistry |
| url | https://www.mdpi.com/1422-0067/24/8/7555 |
| work_keys_str_mv | AT alexanderbdoktorov magneticfieldeffectinbimolecularrateconstantofradicalrecombination AT nikitanlukzen magneticfieldeffectinbimolecularrateconstantofradicalrecombination |