Theoretical study of insulated wires based on polymer chains encapsulated in molecular nanotubes

The structural and electronic properties of a molecular wire (polythiophene (PT)) inside a molecular nanotube (cyclodextrin (CD) molecules) have been investigated. It has been found that the configuration of PT in a CD molecular nanotube is a nearly planar structure and the electronic structure of the polymer chains is almost the same as that of the planar conformation of PT in free space. Moreover, density functional calculations have been performed to investigate the effect of metal contacts on the electronic structure of an insulated molecular wire. The results of the calculations show that attached Au clusters do not modify the electronic properties of the polymer chain and hence do not affect the conductance properties of the studied molecular wires. This indicates that these CD complexes can be used as insulated molecular nanotubes for stabilization of the isolated near-planar configuration of PT