Geometrical and Electronic Properties of Single Molecular Wires

Abstract

In this work, the geometrical properties such as molecular length of the structures, carbon-carbon double and single bonds in a gas phase and in a junction form have been investigated. The electronic properties such as molecular orbitals distribution, charge transport mechanisms, binding energy, electrical conductance, decay constant and current-voltage characteristics of single molecular wires have been studied in this work using density functional theory (DFT) with using of SIESTA and GOLLUM codes and also Gaussian 09 software package. The impact of molecular length on electronic properties of this kind of molecules has been explored and the results show that highest and lowest electrical conductance values are (0.4 and 0.2 μS) respectively. In addition, the computations demonstrate that the high value of decay constant yields low value of electrical conductance. Furthermore, the transport mechanisms through metal|molecule|metal junctions are studied and the results show that the mechanism is LUMO-based conduction mechanism.