Investigation of the structure of and the properties of the potentially tautomeric 1,2,3,4-tetrahydro-5,7-dimethyl-6H-pyrrolo[3,4-d]pyridazine-1,4-diones in the gaseous and aqueous phases using the AM1 semi-empirical method

Guven A., Ogretir C.

JOURNAL OF MOLECULAR STRUCTURE-THEOCHEM, vol.434, pp.7-28, 1998 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 434
  • Publication Date: 1998
  • Doi Number: 10.1016/s0166-1280(98)00072-4
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.7-28
  • Keywords: pyrrolopyridazinones, tautomeric equilibrium, conformation, acidity, basicity, proton affinity, AM1 semiempirical calculation
  • Anadolu University Affiliated: No


Potentially tautomeric 1,2,3,4-tetrahydro-5,7-dimethyl-6H-pyrrolo[3,4-d]pyridazine-1,4-diones and their fixed tautomeric forms have been studied in order to predict their tautomeric equilibrium constants and pK(a) values using semi-empirical AM1 quantum-chemical calculations at the SCF level in the gas phase and in aqueous solution. Hydroxy-oxo forms were found to be more stable than dioxo and dihydroxy forms. The results obtained from the tautomeric equilibria and basicity calculations are in good agreement with experimental data. (C) 1998 Elsevier Science B.V. All rights reserved.