Nitroxoline Molecule: Planar or Not? A Story of Battle between π–π Conjugation and Interatomic Repulsion

Tikhonov, D.S.; Sharapa, D.I.; Otlyotov, A.A.; Solyankin, P.M.; Rykov, A.N.; Shkurinov, A.P.; Grikina, O.E.; Khaikin, L.S.

Авторы: Tikhonov Denis S., Sharapa Dmitry I., Otlyotov Arseniy A., Solyankin Petr M., Rykov Anatolii N., Shkurinov Alexander P., Grikina Olga E., Khaikin Leonid S.
Журнал: The Journal of Physical Chemistry A: Molecules, Clusters, and Aerosols
Том: 122
Номер: 6
Год издания: 2018
Издательство: American Chemical Society
Местоположение издательства: United States
Первая страница: 1691
Последняя страница: 1701
DOI: 10.1021/acs.jpca.7b11364
Аннотация: The conformational properties of the nitrogroup in nitroxoline (8-hydroxy-5-nitroquinoline, NXN) were investigated in the gas phase by means of gas electron diffraction (GED) and quantum chemical calculations, and also with solid-state analysis performed using terahertz time-domain spectroscopy (THz-TDS). The results of the GED refinement show that in the equilibrium structure the NO2-group is twisted by angle φ = 8o ± 3o with respect to the 8-hydroxyoquinoline plane. This is the result of interatomic repulsion of oxygen in the NO2-group from the closest hydrogen, which overcomes the energy gain from the π-π conjugation of nitrogroup and aromatic system of 8-hydroxyoquinoline. The computation of equilibrium geometry using MP2/cc-pVXZ (X = T, Q) shows a large overestimation of the φ value, whilst DFT with cc-pVTZ basis set performs reasonably well. On the other hand DFT computations with double-ζ basis sets yield a planar structure of NXN. The refined potential energy surface of the torsion vibration of nitrogroup in the condensed phase derived from the from THz-TDS data indicates the NXN molecule to be planar. This result stays in good agreement with the previous X-Ray structure determination. The strength of the π-systems conjugation for the NO2-group and 8-hydroxyoquinoline is discussed using NBO analysis, being further supported by comparison of the refined semi-experimental gas-phase structure of NXN from GED with other nitrocompounds.
Добавил в систему: Тихонов Денис Сергеевич

	ИСТИНА	Войти в систему Регистрация
	Интеллектуальная Система Тематического Исследования НАукометрических данных
	Главная Поиск Статистика О проекте Помощь

ИСТИНА

Интеллектуальная Система Тематического Исследования НАукометрических данных

Nitroxoline Molecule: Planar or Not? A Story of Battle between π–π Conjugation and Interatomic Repulsionстатья Исследовательская статья

Прикрепленные файлы