Chromogenic amides of pyridine-2,6-dicarboxylic acid as anion receptors

Abstract

The synthesis of simple, chromogenic pyridine-2,6-dicarboxylic acid amides, derivatives of isomeric nitroanilines and aminonitrophenols, and their ion binding properties are described. The ligands' response to ionic species was examined by naked eye and was studied with the use of UV -vis spectroscopy in DMSO and its mixture with water. The effect of the localisation and the type of the substituents in aromatic rings were discussed. 1 H NMR experiments were carried out to probe the mechanism of anion recognition, i.e. complexation via hydrogen bond formation versus ligand deprotonation. A selective response of N,N 0 -bis(2-hydroxy-4-nitrophenyl)pyridine-2,6-dicarboxamide (L5) towards dihydrogen phosphate was found in both DMSO and DMSO-water (95:5) solvent mixture. The structure of N,N 0 -bis(2-hydroxy-5-nitrophenyl)pyridine-2,6-dicarboxamide (L4) was confirmed by X-ray crystallography.

Sensitive water-soluble fluorescent chemosensor for chloride based on a bisquinolinium pyridine-dicarboxamide compound

“…It is known that, when guest species are bound to a receptor, photophysical characteristics of receptor such as fluorescence intensity and emission wavelength are modified through various mechanism and such changes provide a signal indicating guest binding. Indeed, a variety of signaling mechanism such as PET (Gunnlaugsson et al 2006), excimer formation, (Nishizawa et al 1998) intramolecular change transfer (Reichwagen et al 2004), exciplex formation (Novikov and Boens, 2007;Wagner et al, 2012;Wu et al 2005) and excited state proton transfer (Porel et al, 2013) A c c e p t e d M a n u s c r i p t 11 compound 1-triflate at pH= 5 induces a strong quenching as is shown in Fig. 4A.…”

Synthesis and Structural Characterization of Pyridine-2,6-dicarboxamide and Furan-2,5-dicarboxamide Derivatives

“…M.p. > 300 °C [ 44 ]. 1 H NMR (400 MHz, DMSO- d 6 ), δ [ppm]: 11.35 (s, 2H), 8.97(t, J = 2.1 Hz, 2H), 8.44 (d, J = 7.6 Hz, 2H), 8.34 (m, 3H); 8.04 (m, 2H), 7.75 (t, J = 8.1 Hz, 2H).…”

Ion recognition properties of new pyridine-2,6-dicarboxamide bearing propeller-like pendant residues: multi-spectroscopic approach

“…Amide 1 to the best of our knowledge (according to Chemical Abstracts) has not been described in the literature so far. The amide was prepared in a very simple, well proved synthetic procedure [16,26,38] using 2,6-pyridinecarboxylic acid dichloride and 5-amino-2,2′,2ʺ-tris-2-pyridylamine in the presence of triethylamine as a base in DMF (Scheme 1). The pure compound was obtained with satisfactory yield i.e.…”

“…Pyridine-2,6-dicarboxamides due to the presence of NH groups can also act as anion receptors [20][21][22][23][24][25][26]. Derivatives of dipicolinic acid bearing N-substituted quinoline moieties were proposed for spectrofluorimetric determination of chloride, acetate, and pyrophosphate anions in aqueous solutions [27,28].…”