Theoretical basis for the correlation between energetic, magnetic, and electron density criteria of aromaticity: definition of molecular circuit electric conductance

Using a semiclassical model, a theoretical basis for the correlation between energetic, magnetic, and electron density criteria of aromaticity has been established. The key quantity that links ring current intensity, topological resonance energy, and multicenter electron delocalization is the molecular circuit electric conductance, which is defined as the inverse of the resistance of the molecular circuit to the electron flow when an external electromotive force is exerted on it. The particular case of an external magnetic field applied perpendicularly to the molecular plane is employed here as source of the electromotive force. In addition, it is shown how aromatic stabilization can be estimated quantitatively by means of multicenter electron delocalization in PAHs and nitrogenated polyheterocyclic compounds.