Isotope and Spin Effects Induced by Compression of Paramagnetic Molecules
The zero-point energies (ZPEs) of paramagnetic molecules, free and compressed in a C<sub>59</sub>N paramagnetic cage, were computed. The excess of energy acquired by molecules under compression depended on the deuterium and tritium isotopes which ranged from 6–8 kcal/mol for H<sub>...
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MDPI AG
2022-08-01
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| author | Irene Barashkova Natalia Breslavskaya Luybov Wasserman Anatoly Buchachenko |
| author_facet | Irene Barashkova Natalia Breslavskaya Luybov Wasserman Anatoly Buchachenko |
| author_sort | Irene Barashkova |
| collection | DOAJ |
| description | The zero-point energies (ZPEs) of paramagnetic molecules, free and compressed in a C<sub>59</sub>N paramagnetic cage, were computed. The excess of energy acquired by molecules under compression depended on the deuterium and tritium isotopes which ranged from 6–8 kcal/mol for H<sub>2</sub><sup>+</sup> to 1.0–1.5 kcal/mol for HO<sup>•</sup> and HO<sub>2</sub>. The differences in the ZPEs of compressed isotopic molecules resulted in large deuterium and tritium isotope effects which differed for singlet and triplet spin states. The hyperfine coupling (HFC) constants for protons and <sup>17</sup>O nuclei decreased under compression, confirming the leakage of the unpaired π-electron from the central oxygen atom of guest molecules into the system of π-electrons of the cage, and its distribution over 60 atoms of the C<sub>59</sub>N. The latter seems to be the reason why the nitrogen-14 HFCs for C<sub>59</sub>N remain almost unchanged upon encapsulation of guest molecules. The singlet-triplet splitting is shown to depend on the Coulomb interaction, which controls the sign of the exchange potential. The importance of compression effects on the functioning of enzymes as molecular compressing devices is discussed. |
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| format | Article |
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| issn | 2673-7167 |
| language | English |
| last_indexed | 2024-03-09T22:48:13Z |
| publishDate | 2022-08-01 |
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| spelling | doaj.art-2d277a1ac82a475fa72b75dbeb3dfad32023-11-23T18:25:22ZengMDPI AGPhyschem2673-71672022-08-012325326010.3390/physchem2030018Isotope and Spin Effects Induced by Compression of Paramagnetic MoleculesIrene Barashkova0Natalia Breslavskaya1Luybov Wasserman2Anatoly Buchachenko3Institute of Chemical Physics, Russian Academy of Sciences, 119991 Moscow, RussiaInstitute of Chemical Physics, Russian Academy of Sciences, 119991 Moscow, RussiaInstitute of Chemical Physics, Russian Academy of Sciences, 119991 Moscow, RussiaInstitute of Chemical Physics, Russian Academy of Sciences, 119991 Moscow, RussiaThe zero-point energies (ZPEs) of paramagnetic molecules, free and compressed in a C<sub>59</sub>N paramagnetic cage, were computed. The excess of energy acquired by molecules under compression depended on the deuterium and tritium isotopes which ranged from 6–8 kcal/mol for H<sub>2</sub><sup>+</sup> to 1.0–1.5 kcal/mol for HO<sup>•</sup> and HO<sub>2</sub>. The differences in the ZPEs of compressed isotopic molecules resulted in large deuterium and tritium isotope effects which differed for singlet and triplet spin states. The hyperfine coupling (HFC) constants for protons and <sup>17</sup>O nuclei decreased under compression, confirming the leakage of the unpaired π-electron from the central oxygen atom of guest molecules into the system of π-electrons of the cage, and its distribution over 60 atoms of the C<sub>59</sub>N. The latter seems to be the reason why the nitrogen-14 HFCs for C<sub>59</sub>N remain almost unchanged upon encapsulation of guest molecules. The singlet-triplet splitting is shown to depend on the Coulomb interaction, which controls the sign of the exchange potential. The importance of compression effects on the functioning of enzymes as molecular compressing devices is discussed.https://www.mdpi.com/2673-7167/2/3/18compressed moleculeszero-point energyisotope effectsspin density |
| spellingShingle | Irene Barashkova Natalia Breslavskaya Luybov Wasserman Anatoly Buchachenko Isotope and Spin Effects Induced by Compression of Paramagnetic Molecules Physchem compressed molecules zero-point energy isotope effects spin density |
| title | Isotope and Spin Effects Induced by Compression of Paramagnetic Molecules |
| title_full | Isotope and Spin Effects Induced by Compression of Paramagnetic Molecules |
| title_fullStr | Isotope and Spin Effects Induced by Compression of Paramagnetic Molecules |
| title_full_unstemmed | Isotope and Spin Effects Induced by Compression of Paramagnetic Molecules |
| title_short | Isotope and Spin Effects Induced by Compression of Paramagnetic Molecules |
| title_sort | isotope and spin effects induced by compression of paramagnetic molecules |
| topic | compressed molecules zero-point energy isotope effects spin density |
| url | https://www.mdpi.com/2673-7167/2/3/18 |
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