Optical and magnetic properties of antiaromatic porphyrinoids; Physical Chemistry Chemical Physics; Vol. 19, iss. 38
| Источник: | Physical Chemistry Chemical Physics Vol. 19, iss. 38.— 2017.— [P. 25979-25988] |
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| Примечания: | Title screen Magnetic and spectroscopic properties of a number of formally antiaromatic carbaporphyrins, carbathiaporphyrins and isophlorins with 4n ? electrons have been investigated at density functional theory and ab initio levels of theory. The calculations show that the paratropic contribution to the magnetically induced ring-current strength susceptibility and the magnetic dipole-transition moment between the ground and the lowest excited state are related. The vertical excitation energy (VEE) of the first excited state decreases with increasing ring-current strength susceptibility, whereas the VEE of the studied higher-lying excited states are almost independent of the size of the ring-current strength susceptibility. Strong antiaromatic porphyrinoids, based on the magnitude of the paratropic ring-current strength susceptibility, have small energy gaps between the highest occupied and lowest unoccupied molecular orbitals and a small VEE of the first excited state. The calculations show that only the lowest S0 > S1 transition contributes signficantly to the magnetically induced ring-current strength susceptibility of the antiaromatic porphyrinoids. The decreasing optical gap combined with a large angular momentum contribution to the magnetic transition moment from the first excited state explains why molecules III–VII are antiaromatic with very strong paratropic ring-current strength susceptibilities. The S0 > S1 transition is a magnetic dipole-allowed electronic transition that is typical for antiaromatic porphyrinoids with 4n ? electrons. Режим доступа: по договору с организацией-держателем ресурса |
| Язык: | английский |
| Опубликовано: |
2017
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| Online-ссылка: | http://dx.doi.org/10.1039/C7CP05460B |
| Формат: | Электронный ресурс Статья |
| Запись в KOHA: | https://koha.lib.tpu.ru/cgi-bin/koha/opac-detail.pl?biblionumber=656154 |