Quantum chemical studies on tautomerism, isomerism and deprotonation of some 5(6)-substituted benzimidazole-2-thiones


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Oegretir C., Oeztuerk I. I., TAY N. F.

ARKIVOC, pp.75-99, 2007 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume:
  • Publication Date: 2007
  • Doi Number: 10.3998/ark.5550190.0008.e09
  • Journal Name: ARKIVOC
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.75-99
  • Eskisehir Osmangazi University Affiliated: Yes

Abstract

Acidity constants, pKa values, tautomeric and isomeric equilibrium constants, K-T and K-eq. values, of some 5(6)-substituted benzimidazole-2-thiones and related fixed models, in which the possibility of proton migration is eliminated by replacing the mobile proton with methyl group, were calculated using semi-empirically computed physical and thermodynamic parameters. Full geometry optimization was carried out using semi-empirical AM1, PM3 and PM5 methods. The theoretically calculated acidity constants were compared with the experimental values and a reasonable correlation was observed.