133880-39-4

Upstream product

• 104-94-9 4-methoxy-aniline 
• 708-06-5 2-hydroxynaphthalene-1-carbaldehyde 
• 77761-40-1 N-(p-Methoxyphenyl)-2-oxo-1,2-dihydronaphthyliden-⁽¹⁾-methylamin 

Downstream Products

• 77761-40-1 N-(p-Methoxyphenyl)-2-oxo-1,2-dihydronaphthyliden-⁽¹⁾-methylamin 

Relevant academic research and scientific papers

Imine-based Zwitterion: Synthesis, single-crystal characterization, and computational investigation

The 2?hydroxy-1-naphthaldehyde based Schiff base zwitterions: (E)-1-(((4-methoxyphenyl)-iminio)methyl)naphthalen-2-olate (3a) and (E)-1-(((2?methoxy-4-nitrophenyl)iminio)methyl)-naphthalen-2-olate (3b) have been obtained from the condensation reaction of

Substituent and solvent effects on the proton transfer equilibrium in anils and azo derivatives of naphthol. Multinuclear NMR study and theoretical calculations

The tautomeric equilibrium due to proton transfer is compared in a series of anils of 2-hydroxynaphthalene-1-carbaldehyde and azo derivatives of 2-naphthol. Although structurally similar, these systems suffer different substituent effects on the solution-state proton transfer properties. The comparative study was performed using 1H, 13C and 15N NMR spectroscopy in a variety of solvents. Hartree-Fock ab initio calculations involving relative stability of tautomers and full geometry optimization for the ground state are in agreement with the experimental observations.

GROUND- AND EXCITED-STATE PROTOTROPIC TAUTOMERISM IN ANILS OF AROMATIC α-HYDROXYALDEHYDES STUDIED BY ELECTRONIC ABSORPTION, FLUORESCENCE AND 1H AND 13C NMR SPECTROSCOPIES AND SEMI-EMPIRICAL CALCULATIONS

Proton transfer processes in both the ground and excited states in anils of aromatic α-hydroxyaldehydes (salicylaldehyde, 2-hydroxynaphthalene-1-carbaldehyde and the novel 10-hydroxyphenanthrene-9-carbaldehyde) have been studied by a combination of spectroscopic techniques.Solution 1H and 13C NMR is used to establish the position of the tautomeric equilibria.UV-visible absorption and fluorescence spectral data help to characterize the existence, in all cases, of excited-state intramolecular proton transfer (ESIPT) phenomena.Semi-empirical calculations involving full geometry optimization and calculation of heats of formation for the ground state (AM1) and vertical excitation energies and oscillator strengths (INDO/S) are in agreement with the experimental observations.

13C NMR Spectroscopic and AM1 Study of the Intramolecular Proton Transfer in Anils of Salicylaldehyde and 2-Hydroxynaphthalene-1-carbaldehyde

Tautomeric equilibria in intramolecularly hydrogen bonded Schiff bases is studied on the basis of solution 13C NMR chemical shifts.Variable temperature NMR spectroscopic data and comparison with appropriate models show that while anils of salicaldehyde exist as phenolic tautomers, those of 2-hydroxynaphthalene-1-carbaldehyde exist as equilibrium mixtures containing appreciable amounts of both enol and keto tautomers, the latter being slightly predominant.AM1 results concerning the relative stability of tautomers are in good agreement with the NMR spectroscopic information.

Studies of Chelation. Part 9. Cobalt Complexes of 1--2-naphthol and 1--2-naphthol Ligands. Tautomerism and Reactivity

Spectroscopic characterisation (1H and 13C n.m.r., i.r., Raman, and u.v.-visible) of various 1--2-naphthols, R-Haz (R = 4'-Me, 4'-OMe, 4'-Cl, H, 2'-OMe, 2'-Me, 2'-Cl, and 2'-Br), and 1--2-naphthols, R-Hsb (R = 4'-OMe, 4'-Me, 4'-Cl, H, 4'-Br, 4'-CF3, 4'-CN, 4'-NO2, 2'-OMe, 2'-Me, 2'-CHMe2, 2'-Cl, 2'-CN, and 2'-NO2), in the solid state and in solution in both polar and non-polar solvents has shown that the hydrogen-bonded keto-tautomer is dominant in polar solvents.Reaction of cobalt(II) salts with R-Haz and with R-Hsb in ethanol produces , cis-, and fac- (L=R-az or R-sb).The tautomeric form of the ligand in these complexes is established by vibrational spetroscopy and shown to be predominantly keto (hydrazone, ketoenamine) in , in , and (X = Cl or Br) but predominantly enolimine in .The interconversion of and is established generally: the intermediate, five-co-ordinate is identified in certain cases (R = 4-OMe, 4'-Me, or H).In the chelation process, proton loss follows ring closure and is succeeded by tautomerisation where this occurs.The facility with which the chelating ligand deviates from coplanarity of the benzene and naphthalene rings is a critical feature of the chelation process.The formation of from and from in the presence of air occurs easily and is acid catalysed. is formed only under vigorously oxidising conditions.The isoelectronic ligands R-Haz and R-Hsb should not be regarded as identical in their reactivity towards cobalt(II).