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Chirality responsive helical poly(phenylacetylene) bearing L-proline pendants
Hiroaki Kawamura1, Yoshihisa Takeyama, Miho Yamamoto
1Department of Molecular Design and Engineering, Graduate School of Engineering, Nagoya University, Chikusa-ku, Nagoya 464-8603, Japan.
Chirality
|April 19, 2011
Summary
This study introduces a novel chiral polymer, poly(phenylacetylene) with L-proline, that can selectively trap molecules. This optically active polymer exhibits a unique helix-sense inversion in response to stimuli.
Area of Science:
- Polymer Chemistry
- Chiroptical Materials
- Supramolecular Chemistry
Background:
- Optically active polymers are crucial for chiral recognition and separation.
- Developing polymers with tunable chiroptical properties is an active area of research.
- Poly(phenylacetylene)s offer a versatile platform for creating functional chiral materials.
Purpose of the Study:
- To synthesize and characterize a novel optically active poly(phenylacetylene) with L-proline pendant groups.
- To investigate the chiroptical properties and helical conformation of the synthesized polymer.
- To explore the polymer's ability for enantioselective molecular trapping and stimulus-responsive helix-sense inversion.
Main Methods:
- Polymerization of a novel monomer using a rhodium catalyst in aqueous media.
- Circular dichroism spectroscopy for chiroptical property analysis.
- Investigation of interactions with chiral small molecules and solvent effects.
Main Results:
- Successful synthesis of optically active, cis-transoidal poly(phenylacetylene) (poly-1).
- Poly-1 exhibited intense Cotton effects, indicating a stable one-handed helical conformation.
- Demonstrated helix-sense inversion in response to solvent and chiral guest molecules.
- Enantioselective trapping of 1,1'-2-binaphthol within the polymer's helical cavity was achieved.
Conclusions:
- The L-proline functionalized poly(phenylacetylene) displays significant chiroptical activity and conformational responsiveness.
- The polymer can act as a host for enantioselective molecular recognition in aqueous solutions.
- This work highlights the potential of chiral poly(phenylacetylene)s in developing advanced chiral sensors and separation materials.
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