Jump to main content
Jump to site search

Issue 3, 2016
Previous Article Next Article

A structural, spectroscopic and theoretical study of an o-vanillin Schiff base derivative involved in enol-imine and keto-amine tautomerism

Author affiliations

Abstract

The potassium salt of the Schiff base obtained by condensation of 2-hydroxy-3-methoxybenzaldehyde (o-vanillin) and 2-aminoethanesulfonic acid (taurine) in a methanol potassium hydroxide solution was characterized by crystallographic, spectroscopic and DFT methods. The compound crystallizes in the monoclinic C2/c space group with a = 37.539(4), b = 5.9129(4), c = 26.321(5) Å, β = 121.10(2)° and Z = 8 molecules per unit cell. The crystallographic data reveal that two different anionic molecules, which constitute a tautomeric pair, coexist in the crystal. This finding is supported by FTIR, Raman and electronic measurements in methanol solution. The main crystallographic differences between the bonding structures occur along the shortest chemical path linking the oxygen and the nitrogen atom of the OH and CN group. Both tautomeric forms are stabilized by strong O–H⋯N and N–H⋯O intramolecular hydrogen bonds. Optimized geometrical parameters and calculated spectroscopic features obtained by DFT calculations show a very good agreement with the experimental data. Moreover, 1H NMR, 13C NMR and electronic measurements in DMSO solution show the prevalence of the enol-imine tautomer in this solvent.

Graphical abstract: A structural, spectroscopic and theoretical study of an o-vanillin Schiff base derivative involved in enol-imine and keto-amine tautomerism

Back to tab navigation

Supplementary files

Publication details

The article was received on 06 May 2015, accepted on 08 Jan 2016 and first published on 11 Jan 2016


Article type: Paper
DOI: 10.1039/C5NJ01039J
Citation: New J. Chem., 2016,40, 2730-2740
  •   Request permissions

    A structural, spectroscopic and theoretical study of an o-vanillin Schiff base derivative involved in enol-imine and keto-amine tautomerism

    R. Pis-Diez, G. A. Echeverría, O. E. Piro, J. L. Jios and B. S. Parajón-Costa, New J. Chem., 2016, 40, 2730
    DOI: 10.1039/C5NJ01039J

Search articles by author

Spotlight

Advertisements