Tautomery and acid-base properties of some azoderivatives of benzoylacetone

Mahmudov K. T., Rahimov R. A., Babanlı M., Hasanov P. Q., Pashaev F. G., Gasanov A. G., ...daha çox

Journal of Molecular Liquids, vol.162, no.2, pp.84-88, 2011 (SCI-Expanded, Scopus) identifier

  • Nəşrin Növü: Article / Article
  • Cild: 162 Say: 2
  • Nəşr tarixi: 2011
  • Doi nömrəsi: 10.1016/j.molliq.2011.06.005
  • jurnalın adı: Journal of Molecular Liquids
  • Jurnalın baxıldığı indekslər: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Səhifə sayı: pp.84-88
  • Açar sözlər: Azoderivatives of benzoylacetone, Tautomery, Thermodynamic parameters
  • Açıq Arxiv Kolleksiyası: Məqalə
  • Adres: Bəli

Qısa məlumat

The structural, tautomeric and acid-base properties of the new 1-phenyl-2-(2-hydroxy-3-sulfo-5-chlorophenylhydrazo)butane-1,3-dione (H 2L1), 1-phenyl-2-(2-hydroxy-3,5-disulfophenylhydrazo) butane-1,3-dione (H2L2), 1-phenyl-2-(2-hydroxy-3-sulfo-5- nitrophenylhydrazo)butane-1,3-dione (H2L3) and 1-phenyl-2-(2-hydroxy-4-nitrophenylhydrazo)butane-1,3-dione (H2L 4) were studied using IR, 1H and 13C NMR spectroscopies and potentiometry. The study reveals that H2L 1-4 and the known 1-phenyl-2-(2-hydroxyphenylhydrazo)butane-1,3-dione (H2L5) exist in solution as a mixture of Z-enol-azo-II and hydrazo-III tautomeric forms and that an increase in the solvent polarity shifts the tautomeric balance to the enol-azo form. The thermodynamic parameters of the proton dissociation in H2L1-5 were determined showing that this process is unspontaneous, endothermic and entropically unfavorable. © 2011 Elsevier B.V. All rights reserved.