Molecular Engineering

, Volume 2, Issue 4, pp 349–361 | Cite as

The nature of electronic transitions in absorption spectra of phenyl-substituted 1,3,4-oxadiazoles and 1,3,4-sym-triazoles

  • O. A. Ponomaryov
  • V. G. Mitina
  • S. I. Kotelevsky
Research Note


The electronic absorption spectra of 1,3,4-oxadiazole, 1,3,4-sym-triazole and their phenyl derivatives were calculated within the π-electron approximation, by the PPP-Cl procedure. The nature of the electronic transitions was analysed in terms of special quantum-mechanical excitation indices: excitation-localization indices and charge-transfer indices. An orbital analysis was performed within the framework of the structure-orbital approach. The transitions calculated for unsubstituted azoles should be treated as perturbed ones of the models-cys-azabutadiene molecule. In the case of phenyl derivatives one can classify the transitions as being either local or molecular in character. The dependence of their characteristics on the π-system structure has been studied for the latter transitions. The results of the theoretical treatment are in good agreement with experimental data.

Key words

1,3,4-oxadiazole 1,3,4-sym-triazole phenyl derivatives absorption spectra calculations PPI-CI procedure special excitation indices excitation localization index charge transfer index 


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  1. 1.
    N. A. Popova, E. G. Yushko, B. M. Krasovitskiiet al., Chim. Heterotsikl. Soedin. 1, 26 (1983).Google Scholar
  2. 2.
    V. F. Pedash and Yu. F. Pedash,J. Prikl. Spektrosk. 46, 624 (1987).Google Scholar
  3. 3.
    A. I. Galeyeva, G. V. Maiyer, L. G. Samsonovaet al., Ibid.44, 72 (1986).Google Scholar
  4. 4.
    M. I. Knyazhanskii, P. V. Gilyanovskii, and O. A. Osipov,Chim. Heterotsikl. Soedin. 11, 1455 (1977).Google Scholar
  5. 5.
    A. V. Luzanov,Usp. Chim. 49, 2086 (1980).Google Scholar
  6. 6.
    M. M. Mestechkin,Metod Matritci Plotnosti v Teorii Molekul. Naukova Dumka, Kiev (1977).Google Scholar
  7. 7.
    O. N. Popilin, Diss. Cand. Chim. Nauk., Kharkov (1988).Google Scholar
  8. 8.
    B. G. Plotnikov,Usp. Chim. 49, 327 (1980).Google Scholar
  9. 9.
    G. V. Mayer,Opt. i Spektr. 60, 35 (1986).Google Scholar
  10. 10.
    O. A. Ponomarev, S. I. Kotelevskii, and Yu. F. Pedash,J. Prikl. Spektrosk. 52, 763 (1990).Google Scholar

Copyright information

© Kluwer Academic Publishers 1993

Authors and Affiliations

  • O. A. Ponomaryov
    • 1
  • V. G. Mitina
    • 1
  • S. I. Kotelevsky
    • 1
  1. 1.Research Institute of ChemistryKharkov State UniversityKharkovUkraine

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