Nonracemic Dopant-Mediated Hierarchical Amplification of Macromolecular Helicity in a Charged Polyacetylene Leading to a Cholesteric Liquid Crystal in Water
journal contributionposted on 22.12.2004, 00:00 by Katsuhiro Maeda, Yoshihisa Takeyama, Koichi Sakajiri, Eiji Yashima
Here we show the first example of a helical polyacetylene that forms a lyotropic liquid crystal (LC) through a hierarchical amplification of a macromolecular helicity process in water. The macromolecular helicity with an excess of one helical sense was first induced in the positively charged polyacetylene upon complexation with an extremely small oppositely charged nonracemic dopant through electrostatic interaction in water. Subsequently, the helicity was significantly amplified in the polymer backbone as an almost perfect single-handed helix through self-assembly into supramolecular helical arrays in a lyotropic cholesteric state. The present results will allow the detection of a tiny imbalance in chiral molecules and also provide new approaches for the design of novel water-soluble helical architectures and the construction of new chiral materials in areas such as biotechnology and materials science.