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, at Hartree-Fock and correlated level ofaccuracy (MP2, CCS, CC2, CCSD, and CCSD(T)) have been carried out to investigate whether aromaticity could be relatedto the electric dipole polarizability of planar ring systems. The calculations prove the exaltation of the average property ofconjugated molecules, which is possibly due to their easily polarizable π-electron cloud. On the other hand, theoretical outof-plane polarizability components are smaller in benzene than in any other C6H6 isomer. The aromatic stabilization energiesof monosubstituted five-membered conjugated cyclic molecules increase in the same direction as theoretical out-of-planepolarizabilities.