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Isotope and Spin Effects Induced by Compression of Paramagnetic Moleculesстатья
- Авторы: Barashkova I., Breslavskaya N., Wasserman L., Buchachenko A.
- Журнал: Physchem
- Том: 2
- Год издания: 2022
- Издательство: MDPI
- Местоположение издательства: Basel, Switzerland
- Первая страница: 253
- Последняя страница: 260
- DOI: 10.3390/physchem2030018
- Аннотация: Zero point energies (ZPEs) of paramagnetic molecules, free and compressed in C59N paramagnetic cage, are computed. The excess of energy, acquired by molecules under compression, depends on the deuterium and tritium isotopes ranging from 6−8 kcal/mol for H2+ to 1.0−1.5 kcal/mol for HO• and HO2•. The differences in ZPEs of compressed isotopic molecules result to the large deuterium and tritium isotope effects, different in singlet and triplet spin states. The hyperfine coupling constants for protons and 17O nuclei decrease under compression, certifing 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 C59N. The latter seems to be a reason that the nitrogen-14 HFCs for C59N 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.
- Добавил в систему: Мельников Михаил Яковлевич