Existence of a resonance hybrid structure as a result of proton tautomerism in (+/-)-(E)-4-Bromo-2-[(2,3-dihydroxypropylimino)methyl]phenol racemate

Albayrak C., Kastas G., ODABAŞOĞLU M., Buyukgungor O.

SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY, vol.120, pp.201-207, 2014 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 120
  • Publication Date: 2014
  • Doi Number: 10.1016/j.saa.2013.10.022
  • Journal Name: SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.201-207
  • Keywords: Schiff Base, Tautomerism, Phenol-imine, Keto-amine, X-ray, Enantiomer, MACROCYCLIC LIGAND DESIGN, DENSITY-FUNCTIONAL THEORY, SCHIFF-BASE LIGANDS, HYDROGEN-BOND, TRANSFER EQUILIBRIUM, EXCITATION-ENERGIES, SOLID-STATE, X-RAY, COMPLEXES, COPPER(II)
  • Ondokuz Mayıs University Affiliated: Yes

Abstract

o-Hydroxy Schiff bases have two tautomers known as phenol-imine and keto-amine forms. In the present work, the tautomerism in (E)-4-Bromo-2-[(2,3-dihydroxypropylimino)methyl]phenol compound has been investigated by experimental (XRD, FT-IR and UV-vis) and computational (DFT and TD-DFT) methods. The X-ray diffraction (XRD) study reveals that the title compound favors a resonance hybrid structure of phenol-imine and keto-amine forms in the solid state rather than having these forms separately or jointly. Experimental UV-vis study of proton transfer process in solvent media (Benzene, DMSO and EtOH) shows the preference of phenol-imine form in benzene while both phenol-imine and keto-amine characteristics are present in EtOH and DMSO. (C) 2013 Elsevier B.V. All rights reserved.