Metal‐cation‐induced chiroptical switching for poly(phenylacetylene) bearing a macromolecular ionophore as a graft chain
Metal‐cation‐induced chiroptical switching for poly(phenylacetylene) bearing a macromolecular ionophore as a graft chain
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DOI：
10.1002/pola.21090
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发表时间：
2005-12
期刊：
影响因子：
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通讯作者：
I. Otsuka;R. Sakai;T. Satoh;R. Kakuchi;H. Kaga;T. Kakuchi
中科院分区：
文献类型：
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作者：
I. Otsuka;R. Sakai;T. Satoh;R. Kakuchi;H. Kaga;T. Kakuchi
通过末端官能化的(1-→-6)-2，5-脱水-3，4-二-O-乙基-D-葡萄糖醇与苯乙炔共聚，合成了以多糖离子载体为接枝链的聚苯乙炔(共聚物4)。共聚物4在共轭聚合物主链的长吸收区域(280-500 nm)表现出分离型圆二色(CD)，且CD模式随外界刺激(如溶剂和温度)而变化。这表明4在聚乙炔主链上以单手螺旋构象为主。通过大分子离子载体单元与所选择的金属阳离子，即Ba2+，Pb2+，Sr2+，Na+和Li+之间的络合物的形成，4的CD图谱完全颠倒。这表明共聚物4通过与非手性无机金属阳离子的主客体络合发生了螺旋-螺旋转变。©2005威利期刊公司J Polym Sci Part A：Polym Chem 43：5855-5863,2005
A poly(phenylacetylene) bearing a polycarbohydrate ionophore as a graft chain (copolymer 4) was synthesized by the copolymerization of end-functionalized (1→6)-2,5-anhydro-3,4-di-O-ethyl-D-glucitol with a 4-ethynylbenzoyl group (macromonomer 2) with phenylacetylene. Copolymer 4 showed a split-type circular dichroism (CD) in the long absorption region of the conjugated polymer backbone (280–500 nm), and the CD pattern varied in response to external stimuli, such as the solvents and temperature. This suggested that 4 had a predominantly one-handed helical conformation in the polyacetylene backbone. The CD pattern of 4 was completely inverted by the formation of a complex between the macromolecular ionophore units and the selected metal cations, that is, Ba2+, Pb2+, Sr2+, Na+, and Li+. This suggested that copolymer 4 underwent a helix–helix transition through the host–guest complexation with achiral inorganic metal cations. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5855–5863, 2005