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Remote Control of One-Handed Helicity in Polyacetylenes through Flexible Spacers in Water: Impact of the Spacer Length |
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| Authors: | Dr Tomoyuki Ikai Koshi Nakamura Kosuke Mizumoto Dr Kosuke Oki Prof Eiji Yashima |
| Institution: | 1. Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Chikusa-ku, Nagoya, 464-8603 Japan;2. Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Chikusa-ku, Nagoya, 464-8603 Japan
Contribution: Data curation (lead), Formal analysis (lead);3. Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Chikusa-ku, Nagoya, 464-8603 Japan Contribution: Data curation (supporting), Formal analysis (supporting) |
| Abstract: | We report the unprecedented sergeants and soldiers (S&S)-type remote control of one-handed helicity in copolymers of chiral/achiral biphenylylacetylenes bearing amphiphilic oligo(ethylene glycol) (OEG) side chains. A small amount of chiral binaphthyl residues (≤10 mol %) introduced at the terminal of the achiral OEG spacers as many as 80 bonds away from the polymer backbones induced a complete one-handed helix in water through preferential intramolecular encapsulation of the binaphthyl groups within a cavity of the copolymers. A fully one-handed helix can be induced virtually independent of the OEG spacer length and concentrations. At a specific spacer length, however, its helix-sense was inverted. The copolymers also form an excess one-handed helix in organic solvents in an OEG spacer-length dependent manner, yet far from the polymer backbones. We show the superiority of the present covalent-bond driven S&S-type remote helicity control over the corresponding noncovalent helicity induction approach. |
| Keywords: | Amplification of Asymmetry Helical Polymers Helicity Induction Inclusion Complexation Polyacetylenes |