HELICAL POLYACETYLENE SYNTHESIZED WITH A CHIRAL NEMATIC REACTION FIELD

Helical polyacetylene was synthesized under an asymmetric reaction fie ld consisting of chiral nematic (N) Liquid crystals (LCs). The chiral nematic LC was prepared by adding a chiroptical binaphthol derivative as a chiral dopant to a mixture of two nematic LCs. Acetylene polymer izations were carried out using the catalyst titanium tetra-n-butoxide -triethylaluminum dissolved in the chiral nematic LC solvent. The poly acetylene film was shown by scanning electron microscopy to consist of clockwise or counterclockwise helical structure of fibrils. A Cotton effect was observed in the region of the pi --> pi transition of the polyacetylene chain in circular dichroism spectra. The high electrical conductivities of similar to 1500 to 1800 siemens per centimeter afte r iodine doping and the chiral helicity of these films may be exploite d in electromagnetic and optical applications.