5-Aryl-6-arylthio-2,2′-bipyridine and 6-Arylthio-2,5-diarylpyridine Fluorophores: Pot, Atom, Step Economic (PASE) Synthesis and Photophysical Studies

Autor: Ilya N. Egorov, Olga S. Taniya, Grigory V. Zyryanov, Maria I. Savchuk, Valery N. Charushin, Dmitry S. Kopchuk, Sougata Santra, Oleg N. Chupakhin, I. L. Nikonov
Rok vydání: 2021
Předmět:
Zdroj: Journal of Fluorescence. 31:1099-1111
ISSN: 1573-4994
1053-0509
Popis: A PASE (pot, step, atom, economic) synthetic approach to 5-aryl-6-arylthio-2,2′-bipyridine and 6-arylthio-2,5-diarylpyridine ligands/fluorophores has been reported via SNH in 6-aryl-5H-1,2,4-triazines/aza-Diels-Alder reaction sequence. In this article, the “1,2,4-triazine” methodology was successfully used for the synthesis of C6-thiophenol-substituted (2,2′-bi)pyridines as it is well known that thio-substituted (bi)pyridines and their aza-analogs are of wide practical interest. The photophysical properties of the obtained compounds are studied and compared with those reported earlier for 6-substituted 2,2′-bipyridines. The influence of the nature of substituents in the 6-arylthio(bi)pyridine core on the photophysical properties is discussed. It was observed that the new compounds exhibited promising photophysical properties and could be considered as potential push-pull fluorophores. In addition, they demonstrated greater Stokes shift values compared to the previously described 6-H, 6-arylamino and 6-pentafluoro-2,2′-bipyridines and higher fluorescence quantum yields values compare to pentafluorophenyl-substituted 2,2′-bipyridines. Depending on a nature of (bi)pyridine fluorophore LE (locally excited) and/or ICT (intramolecular charge transfer) state were prevailing in emission spectra.
Databáze: OpenAIRE
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