Helical polyacetylene--origins and synthesis.
We present the origins and synthesis of helical polyacetylene (H-PA) by focusing on its peculiar spiral morphology. Interfacial polymerization of acetylene was carried out in an asymmetric reaction field consisting of chiral nematic liquid crystal (N*-LC) and Ziegler-Natta catalyst. As the N*-LC is composed of nematic liquid crystal and a chiral compound such as a binaphthyl derivative with either the R- or S-configuration, the screw directions of the polyacetylene chain and fibril bundle--and even the spiral morphology--are rigorously controlled by the chirality of the selected compound. Interestingly, the screw directions of the fibril and the bundle in H-PA were found to be opposite to that of N*-LC. It is worthwhile to emphasize that the hierarchical spiral morphology involving the primary to higher order structure is generated in a synthetic polymer such as polyacetylene by using N*-LC as an asymmetric polymerization solvent.
Akagi
Kazuo
K
Department of Polymer Chemistry; Kyoto University; Katsura; Nishikyo-ku, Kyoto 615-8510, Japan. akagi@star.polym.kyoto-u.ac.jp
Mori
Taizo
T