6‐Arylamino‐2, 2′‐bipyridine "Push‐Pull" Fluorophores: Solvent‐Free Synthesis and Photophysical Studies. Issue 16 (24th April 2018)

• Record Type: Journal Article
• Authors: Kopchuk, Dmitry S.; Krinochkin, Alexey P.; Starnovskaya, Ekaterina S.; Shtaitz, Yaroslav K.; Khasanov, Albert F.; Taniya, Olga S.; Santra, Sougata; Zyryanov, Grigory V.; Majee, Adinath; Rusinov, Vladimir L.; Chupakhin, Oleg N.
• Is Part Of: ChemistrySelect. Volume 3:Issue 16(2018)
• Page Start: 4141
• Page End: 4146
• Publication Date: 2018-04-24
• Subjects: aza-Diels-Alder reaction -- 2, 2′-bipyridines -- ipso-substitution -- photophysical properties -- solvent-free; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/slct.201800220
• Languages: English
• ISSNs: 2365-6549

Abstract

Abstract: This work describes a solvent‐free approach towards "push‐pull" fluorophores based on 5‐aryl‐2, 2′‐bipyridines bearing the residues of various anilines at the α‐position of the edge pyridine cycle. We have also studied the possibility of varying (het)aromatic‐substituents at C5 position of the resulted 2, 2′‐bipyridines as well as the substituents in the aniline residues. The structures of products were confirmed based on the 1 H and 13 C NMR spectroscopic data, mass spectrometry, elemental analysis and X‐ray diffraction analysis. The photophysical features of the synthesized compounds have been investigated. The fluorescence emission of two key compounds was studied in solvents by varying polarities. It was demonstrated that an increase in the solvent polarity led to an increase in the Stokes shift. The linear dependence of the Stokes shift of the fluorophores on the increasing of the solvent nature was demonstrated by using the Lippert–Mataga plot. The fluorescence quenching response of the fluorophores towards metal cations was also demonstrated. Abstract : Synthesis of 5‐aryl‐2, 2′‐bipyridines substituted with various anilines in C6 position of pyridine cycle was developed by means of the combination of ipso ‐substitution of cyano group at the C5 position of 6‐aryl‐3‐(2‐pyridyl)‐1, 2, 4‐triazines and followed by aza ‐Diels‐Alder reaction with such dienophiles. The reactions underwent smoothly under solvent‐free reaction conditions. In addition, photophysical properties of the obtained products were studied.