DANIELA DASCĂLU, DELIA ISAC, A. PAHOMI, ADRIANA ISVORAN^#
Department of Biology-Chemistry and Advanced Environmental Research Laboratories, West University of Timișoara, Romania

Some physical and chemical properties of the hydrocarbons, of the acyclic and cyclic
ions and of the heterocycles with nitrogen can be correlated with static reactivity parameters,
described by the molecular orbitals method. The results of the calculations made using Hückel
method are listed both as energy parameters and as parameters regarding π-electron density
distribution. These indices point out the relative reactivity of planar compounds in a series and the
sites in a molecule, where substitutions, additions, or other reactions occur. The characterization of
the stability and the aromaticity of the investigated organic structures is undertaken in order to
compare their chemical behaviour. Taking into account the calculations based on Hückel method and
the literature data, aromatic and anti-aromatic compounds are compared to the non-aromatic planar
systems. Also, the ranking of the aromatic ions according to their stability allows the correlation of
their energy indices with the oxidizing and reducing character.
Key words: delocalization energy, aromaticity, wavenumber, hydrocarbons, Hückel method,
chemical reactivity, free valence, electronic density.

Corresponding author’s e-mail: adriana.isvoran@e-uvt.ro

Full text: PDF