Polymer Synthesis Based on Triple-bond Building Blocks

Construction of predominantly one-handed helical polyacetylenes with a desired helix sense utilizing noncovalent chiral interactions with nonracemic chiral guest compounds based on a supramolecular approach is described. As with the conventional dynamic helical polymers possessing optically active pendant groups covalently bonded to the polymer chains, this noncovalent helicity induction system can show significant chiral amplification phenomena, in which the chiral information of the nonracemic guests can transfer with high cooperativity through noncovalent bonding interactions to induce an almost single-handed helical conformation in the polymer backbone. An intriguing ‘‘memory effect’’ of the induced macromolecular helicity is observed for some polyacetylenes, which means that the helical conformations induced in dynamic helical polyacetylene can be transformed into metastable static ones by tuning their helix-inversion barriers. Potential applications of helical polyacetylenes with controlled helix sense constructed by the ‘‘noncovalent helicity induction and/or memory effect’’ as chiral materials are also described. & Katsuhiro Maeda maeda@se.kanazawa-u.ac.jp & Eiji Yashima yashima@chembio.nagoya-u.ac.jp 1 Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan 2 Department of Molecular Design and Engineering, Graduate School of Engineering, Nagoya University, Chikusa-ku, Nagoya 464-8603, Japan 123 Top Curr Chem (Z) (2017) 375:72 DOI 10.1007/s41061-017-0161-4 1 Reprinted from the journal Chapter 1 was originally published as Maeda, K. & Yashima, E. Top Curr Chem (Z) (2017) 375: 72. DOI 10.1007/s41061-017-0161-4.