|
ИСТИНА |
Войти в систему Регистрация |
ИСТИНА ИНХС РАН |
||
First Subphthalocyanine Analogue with Fused 6H‐1,4‐diazepine Ring and its Conversion to Aminobenzamide Derivativeстатья
Статья опубликована в высокорейтинговом журнале
Статья опубликована в журнале из списка Web of Science и/или Scopus- Авторы: Skvortsov Ivan A., Chufarin Alexey E., Zaitsev Mark V., Kirakosyan Gayane A., Stuzhin Pavel A.
- Журнал: Asian Journal of Organic Chemistry
- Том: 12
- Номер: 11
- Год издания: 2023
- DOI: 10.1002/ajoc.202300425
- Аннотация: Mixed cyclization of 5,7-diphenyl-6H-1,4-diazepine 2,3-dicarbonitrile and tetrafluorophthalonitrile in the presence of boron trichloride affords along with symmetrical perfluorinated subphthakocyanine, [F12sPc], two novel subporphyrazine-type products which were isolated by column chromatography and characterized by mass-sprectometry, NMR, IR, UV-VIS and fluorescent spectroscopy. It was established that co-cyclomerization of dinitriles is accompanied by electrophilic chlorination of 1,4-diazepine ring by evolved Cl2 resulting in formation of dibenzosubporphyrazine [F8sPc1] with fused 6-chloro-5,7-diphenyl-6H-1,4-diazepine fragment. According to DFT modelling and 1H NMR data, a more stable diastereomer with an axial Cl atom is formed and no inversion of the 1,4-diazepine ring is observed. Hydrolytic cleavage of the 1,4-diazepine fragment in [F8sPc1] is observed upon chromatography or in the presence of a strong acid (CF3COOH) and leads to 2-amino-3-benzamide substituted dibenzo subporphyrazine [F8sPc2]. Fluorescence of [F8sPc1] (ΦF=0.03) is ca 10 times lower than for [F12sPc] (ΦF=0.28) due to the combined effect of intramolecular charge transfer (ICT) from the donor diazepine ring to the acceptor sPc macrocycle and heavy atom effect of chlorine. Fluorescence of [F8sPc2] is almost completely quenched by ICT from −NH2 group to the electron-deficient subporphyrazine core (ΦF<0.001), but addition of acid leads to protonation of the amino group and switch-ON the fluorescence. Therefore, aminobenzamide substituted subporphyrazines can be considered as perspective pH-sensitive fluorophores.
- Добавил в систему: Скворцов Иван Александрович