Can aromaticity be connected with molecular polarizability? A theoretical study of benzene isomers and five-membered heterocyclic molecules.

Extended calculations of molecular electric dipole polarizability tensor,atHartree-Fock and correlated level of accuracy (MP2, CCS, CC2, CCSD, and CCSD(T))show that the out-of-planecomponent can be used asa measure of aromaticity within the series of benzene isomers. The resultsseem to imply that theelectron cloud of planar conjugated systems in the presence of electricfield perpendicular to themolecular plane is comparatively less polarizable on increasing thearomatic character.