Polymer Sciences Open Access

Emerging stretched and contacted helices and its stimuli induced mutual conversion of substituted polyacetylenes prepared with an organo-rhodium catalyst

Polymer-Biopolymer Chemistry

March 18-19, 2019 | Amsterdam, Netherlands

Masayoshi Tabata and Yasuteru Mawatari

Muroran Institute of Technology, Japan

Keynote: Polym Sci

Abstract:

We have revealed that monosubstituted polyacetylenes (SPA)s which were prepared with a [Rh(norbornadiene)Cl]2 in the presence of amine or alcohol as co-catalyst have highly stereoregular main-chains with helical cis-cisoid and/or cis-transoid structures which have various helical pitches depending on the side chain structure (Fig. 1). The SPAs with a re1lative small side chain like an aliphatic group generate a contracted cis-cisoid helix structure and in contrast in the case of a stretched is created. Furthermore, in the case of aromatic side chains, an interesting mutual conversion between the contracted and stretched helices was induced by an external stimulus, i.e., heat treatment, solvent vapor, and soak insolvent, accompanied with a drastic colour change in the solid state. The cis-transoid and cis-cisoid helices constructed from the aliphatic polyacetyl-ene ester main chain in solution showed an interesting accordion-like helix oscillation, HELIOS between their helices where restricted rotations around the O-C bond in the ester side-chain are dynamically synchronized.

Biography :

Masayoshi Tabata has completed his PhD from Hokkaido University, Japan and Postdoctoral studies from UK and Sweden. After that, he became an Assistant Professor and Associated Professor at Hokkaido University, and Professor of Muroran Institute of Technology, Japan. Moreover, he also became a Senior Research Director at AIST, Tsukuba, Japan, and Guest Professor at Paris University in France.

E-mail: tabata@mmm.muroran-it.ac.jp