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Synthesis of Cyclic Polymers and Characterization of Their Diffusive Motion in the Melt State at the Single Molecule Level
Published on: September 26, 2016
Two-dimensional surface chirality control by solvent-induced helicity inversion of a helical polyacetylene on
Shin-ichiro Sakurai1, Kento Okoshi, Jiro Kumaki
1Yashima Super-structured Helix Project, Exploratory Research for Advanced Technology (ERATO), Japan Science and Technology Agency (JST), 101 Creation Core Nagoya, Shimoshidami, Moriyama-ku, Nagoya 463-0003, Japan.
Journal of the American Chemical Society
|April 28, 2006
Summary
This study shows helical polymers can flip their handedness in different solvents. This surface chirality change was visualized using atomic force microscopy.
Area of Science:
- Polymer Chemistry
- Supramolecular Chemistry
- Surface Science
Background:
- Helical polymers exhibit unique chiroptical properties.
- Solvent-induced conformational changes in polymers are known.
- Controlling supramolecular assembly is crucial for advanced materials.
Purpose of the Study:
- To provide direct evidence of macromolecular helicity inversion in helical poly(phenylacetylene)s.
- To investigate the self-assembly of diastereomeric helical structures in different solvents.
- To visualize and quantify solvent-induced changes in surface chirality.
Main Methods:
- Atomic Force Microscopy (AFM) for high-resolution surface imaging.
- X-ray diffraction (XRD) for structural analysis of polymer films.
- Utilizing poly(phenylacetylene)s with chiral alanine pendants and alkyl chains.
Main Results:
- Direct visualization of macromolecular helicity inversion using AFM.
- Formation of ordered 2D helix bundles on graphite with controlled pitch and handedness.
- Demonstration of helicity inversion from polar to nonpolar solvents and vice versa.
- Quantification of structural changes via X-ray diffraction.
Conclusions:
- Macromolecular helicity inversion is directly observable and controllable via solvent manipulation.
- Helical polymers can form ordered supramolecular structures with tunable properties.
- Surface chirality can be dynamically altered, offering potential for chiral sensing and responsive materials.
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