Spectroscopic studies, antimicrobial activities, and crystal structure of N-[2-hydroxy-1-naphthylidene]3, 5-bis(trifluoromethyl)aniline

Structural investigation on phenyl‐ and pyridin‐2‐ylamino(methylene)naphthalen‐2(3H)‐one. Substituent effects on the NMR chemical shifts

“…For example, compound 4 was reported by Ranganathan et al 36, 37 However, the authors assigned the peak at δ = 15.40 ppm to an OH group, which is in contrast to the results obtained in the present study. Compounds 6 , 10 and 12 were reported to exist as a keto tautomer from X‐ray crystallographic studies, a finding consistent with our solution data 38, 42–44. Issa et al 39 reported compound 1 which possesses a pyridyl moiety and hydroxy functionality in its structure.…”

“…Tautomeric equilibrium reflects the transfer of a proton from a nitrogen atom to an oxygen atom in Schiff bases. This class of compounds has important biological applications,1–5 interesting electronic properties,6–8 and may exhibit photochromic and thermochromic characteristics 9–45. There have been several reports in the literature providing experimental evidence for the formation of enol–keto tautomers in solution and in solid state of Schiff bases.…”

Synthesis, spectroscopic studies and crystal structure of (E)-2-(2,4-dihydroxybenzylidene)thiosemicarbazone and (E)-2-[(1H-indol-3-yl)methylene]thiosemicarbazone

“…The Schiff bases show absorption in the range greater than 400 nm in polar and nonpolar solvents [11][12][13]. It is point out that the new band belongs to the keto-amine form of the Schiff bases with OH group in ortho position to the imino group in polar and nonpolar solvents in both acidic and basic media [11][12][13][16][17][18][19]. The compound 1 showed no absorption above 400 nm in DMSO.…”

“…Thiosemicarbazones are an important group of multidentate ligands with potential binding sites available for a wide variety of metal ions [8][9][10]. Tautomerism in Schiff bases with OH group in ortho position to the imino group both in solution and in solid state were investigated using spectroscopy and X-ray crystallography techniques [11][12][13][14][15][16][17][18][19]. Schiff bases with OH group in ortho position to the imino group are of interest mainly due to the existence of either OAH.…”

DFT calculation, biological activity, anion sensing studies and crystal structure of (E)-4-chloro-2-((pyridin-2-ylimino)-methyl)phenol

“…These bond distances are comparable with those of compounds previously reported as phenol-imine. [31][32][33] The dihedral angle between the C1-C6 and pyridine rings (C8-N2) is 4.38(8)°. The molecular structure is stabilized by an intra-molecular O1-H1 … N1 hydrogen bond (Fig.…”