Electric and magnetic properties computed for valence bond structures: is there a link between pauling resonance energy and ring current?
To establish the link between the aromaticity descriptors based on the Pauling resonance energy and the molecular properties, the electric (polarizability) and magnetic (magnetizability) field response properties have been calculated using the valence bond approach for various molecules and their individual Kekulé resonance structures. The results show that there is no direct relationship between the Pauling resonance energy and the properties; the response properties are weighted averages of the properties of the individual structures. According to the aromaticity criteria based on molecular properties, one-structure benzene would be aromatic; thus, concerning molecular properties, spin-coupled bonds do not behave like localized bonds in Lewis structures, with which they are usually associated.
Havenith
Remco W A
RW
Debye Institute, Theoretical Chemistry Group, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands. r.w.a.havenith@chem.uu.nl