Chemical Papers

, Volume 62, Issue 3, pp 294–301 | Cite as

On the tautomerism of 1-phenyl-3-substituted-pyrazol-5-ones and their photoinduced products — experimental and theoretical UV spectral analysis

  • Atanas G. ChapkanovEmail author
  • Bojidarka B. Koleva
  • Michail G. Arnaudov
  • Ivan K. Petkov
Original Paper


A detailed experimental and theoretical UV-spectral analysis of the tautomeric forms of 3-methyl-1-phenyl pyrazol-5-one and 1,3-diphenyl pyrazol-5-one as well as of the UV-irradiated photoinduced products of the latter compound were carried out. The experimental UV-spectra were compared with the theoretical ones obtained by CIS/6-31G**. Selected geometrical parameters of the different tautomers were estimated by ab initio calculations using the RHF/6-31G** level of theory and basis set, which have also been discussed with a view to the corresponding UV-results.


pyrazol-5-ones tautomerism UV-spectra theoretical analysis photoisomerization 


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Copyright information

© Versita 2008

Authors and Affiliations

  • Atanas G. Chapkanov
    • 1
    Email author
  • Bojidarka B. Koleva
    • 2
  • Michail G. Arnaudov
    • 2
  • Ivan K. Petkov
    • 2
  1. 1.Department of ChemistrySouth-West University Neofit RilskiBlagoevgradBulgaria
  2. 2.Faculty of ChemistryUniversity of Sofia St. Kliment OhridskiSofiaBulgaria

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