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Theoretica chimica acta

, Volume 5, Issue 2, pp 102–111 | Cite as

The electronic structure of tetra-azapentalene

  • L. Paoloni
  • P. Gramaccioni
  • A. Vaciago
Commentationes

Abstract

The ultraviolet absorption spectra in various solvents and a study of the electronic structure of 1, 3a, 4, 6a-tetra-azapentalene are reported. The ASMO-SCF-CI method in the Pariser-Parr-Pople approximation has been used with different alternatives for evaluating theγ pq and the (A: pp) integrals. Only two out of the six different set of calculations have given an acceptable prediction of the first π* ←π transition; moreover the introduction of penetration integrals is found necessary for a correct prediction of the sequence of the N-N bond lengths based on the sequence of the bond orders.

Keywords

Physical Chemistry Inorganic Chemistry Organic Chemistry Absorption Spectrum Bond Length 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Resume

Les spectres d'absorption ultraviolet dans des differents solvents et un étude sur la structure électronique du 1, 3a, 4, 6a-tetra-azapentalene sont exposés. La méthode ASMO-SCF-CI dans l'approximation de Pariser-Parr-Pople, a été employée avec plusieures alternatives pour 1e calcul des intégralesγ pq et (A: pp). Entre les six differents calculs accomplis, deux seulement ont donné une prédiction acceptable pour la prémière transitionπ* On a trouvé que pour une correcte prédiction de la séquence des longueures N-N sur la base des indices de liaison il faut introduir dans les calculs les integrales de pénetration.

Zesummenfassung

Die UV-Absorptionsspektren von 1, 3a, 4, 6a-Tetraazapentalen in verschiedenen Lösungsmitteln werden angegeben. Die Elektronenstruktur dieser Verbindung wurde mittels SCF-CI-Rechnungen mit den Näherungen von Pariser-Parr-Pople and verschiedenen Sätzen vonγ pq und (A: pp)-Integralen ermittelt, wobei zwei der sechs Sätze einen annehmbaren π-π*-Über-gang liefern. Sollen sich die Werte der N-N-Bindungsordnungen in Übereinstimmung mit denentsprechenden Bindungslängen ergeben, so können die Durchdringungsintegrale nicht vernachlässigt werden.

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Copyright information

© Springer-Verlag 1966

Authors and Affiliations

  • L. Paoloni
    • 1
  • P. Gramaccioni
    • 2
  • A. Vaciago
    • 2
  1. 1.Laboratories of ChemistryIstituto Superiore di SanitàRome
  2. 2.Department of PhysicsCatholic University Medical SchoolRomeItaly

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