Functionalized oligoynes: comparison of theoretical parameters with experimental single molecule conductance

Abstract

The single molecule conductance values of five polyyne molecules (BT[4], BTh[4], CN[4], Py[4], NO2[4]) were reported experimentally previously. In the present study, we compared the experimentally obtained single molecule conductance values of these five molecules with the theoretical parameters which define their single molecule conductance. Molecular orbitals, bond length alternation (BLA), transport barrier, reorganization energy, HOMO-LUMO gap, and excitation energy were the considered theoretical parameters since these parameters were reported to have the potential to influence the single molecule conductance. A modification in BLA occurs when interacting with metal surface due to charge transfer; it was seen that this modified BLA correlates well with the reported single molecule conductance values. Also, BT[4] and Py[4] showed higher binding energies compared to the other cases showing good correlation with the experimental results.