Direct observation of helical polysilane nanostructures by atomic force microscopy

The nanostructure of a single quantum wire of the silicon: poly[n-decyl-(S)-2-methylbutylsilane] molecule on a hydrophobic ultrasmooth sapphire plate has been observed by atomic force microscopy (AFM). The backbone structure of this molecule is considered to be a rigid rodlike helix and to be fixed securely into a preferential single-screw-sense. The obtained result of the AFM shows that the polysilane molecule, with a length of about 2 mu m, consists of very long rod-like segments linked by kinks as expected for this backbone structure. Networklike aggregated nanostructures of these molecules were also observed for the sample prepared from concentrated solvents.