title: Reversible polyphenylacetylene helix conversion driven by a thermoresponsive rotaxane switch in the solid state.
abstract: The reversible helical pitch change of polyphenylacetylenes by a thermoresponsive rotaxane switch inserted into the side chain was demonstrated through an accompanying color change. Similar to an ethynyl rotaxane monomer, the corresponding polyphenylacetylene having a rotaxane moiety in its side chain exhibited a reversible helical pitch change induced by the thermoresponsive rotaxane switch, i.e., the amine/ammonium salt was converted by treatment with trichloroacetic acid (TCA) and subsequent heating, which led to thermal decomposition of TCA to chloroform and carbon dioxide. Such a rotaxane switch caused the helical pitch change and the accompanying color change of the polymer main chain in both solution and solid state.
authors: Department of Organic and Polymeric Materials, Tokyo Institute of Technology, 2-12-1, O-okayama, Meguro-ku, Tokyo 152-8552, Japan. ttakata@polymer.titech.ac.jp.
authors: Nan
authors: N
authors: Zhu
authors: Department of Organic and Polymeric Materials, Tokyo Institute of Technology, 2-12-1, O-okayama, Meguro-ku, Tokyo 152-8552, Japan. ttakata@polymer.titech.ac.jp and Advanced Catalytic Transformation of Carbon Utilization (ACT-C), JST, O-okayama, Meguro-ku, Tokyo 152-8552, Japan.
authors: Kazuko
authors: K
authors: Nakazono
authors: Department of Organic and Polymeric Materials, Tokyo Institute of Technology, 2-12-1, O-okayama, Meguro-ku, Tokyo 152-8552, Japan. ttakata@polymer.titech.ac.jp and Advanced Catalytic Transformation of Carbon Utilization (ACT-C), JST, O-okayama, Meguro-ku, Tokyo 152-8552, Japan.
authors: Toshikazu
authors: T
authors: Takata
mesh_terms: D000114:Acetylene / Q000031:analogs & derivatives* / Q000737:chemistry; D043862:Rotaxanes / Q000737:chemistry*; D060327:Solid-Phase Synthesis Techniques; D013696:Temperature; D014238:Trichloroacetic Acid / Q000737:chemistry*
chemical_list: D043862:Rotaxanes; C044736:phenylacetylene; D014238:Trichloroacetic Acid; D000114:Acetylene