Helical polyacetylene synthesized under asymmetric reaction field constructed with chiral nematic liquid crystals

Helical polyacetylene was synthesized under asymmetric reaction field const ructed with chiral nematic liquid crystal (LC). The chiral nematic LC was p repared by adding a chiral phenylcyclohexyl (PCH) derivative, (R)- or (S)-P CH308*, as a dopant, into an equi-weighted mixture of two kinds of nematic LCs. Acetylene polymerization was carried out with Ti(O-n-Bu)(4) - Et3Al ca talyst dissolved in the chiral nematic LC. It is found from SEM measurement s that the polyacetylene films is composed of helical fibrils that are bund les of polyene chains. CD spectrum of the polyacetylene film showed positiv e or negative Cotton effect, depending on the helicity of the chiral nemati c LC.