Liquid Crystallinity Enforced Chirality Transfer from Chiral Monosubstituted Polyacetylene Copolymer to Poly(p-phenylene ethynylene)

Chiral liquid crystalline (LC) monosubstituted polyacetylene (mono-PA) copolymers, consisting-of an LC acetylene monomer unit and an asymmetric center-containing chiral acetylene monomer unit, have been synthesized. The former has a phenylcyclohexyl (PCH) mesogen linked with a trimethylene spacer, and the latter has an (R)-/(S)-1-methylpropargyl undecanoate structure. By varying the feed ratio of the acetylene monomers, a facile method for tuning the LC and the chiral functionality in the mono-PA copolymers was developed. The synergistic effects-between the LC and the chiral monomer units were employed to enable the chirality transfer from, the mono-PA copolymer to the achiral LC conjugated polymer, poly(p-phenylene ethynylene) [LC-PPE]. The utilization of chiral LC mono-PA copolymers for the chirality transfer of LC-PPE is reported, wherein the LC monomer units enhance the interpolymer interactions through increased miscibility in the LC phase, while the chiral monomer units induce chirality in the LC-PPE main chain.