Host–guest complexation‐triggered chiroptical change of poly(phenylacetylene)s bearing binaphthocrown ether moieties on the main chain
Host–guest complexation‐triggered chiroptical change of poly(phenylacetylene)s bearing binaphthocrown ether moieties on the main chain
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DOI：
10.1002/pola.23881
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发表时间：
2010-03
期刊：
影响因子：
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通讯作者：
R. Sakai;T. Yonekawa;I. Otsuka;R. Kakuchi;T. Satoh;T. Kakuchi
中科院分区：
文献类型：
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作者：
R. Sakai;T. Yonekawa;I. Otsuka;R. Kakuchi;T. Satoh;T. Kakuchi
采用铑催化剂对具有不同氧乙烯链长度的二乙炔单体进行环聚合，得到了重复单元（2a-c）中具有不同空腔大小的手性冠醚的新型聚苯乙炔。在聚合物的圆二色光谱中，在350 ~ 500 nm范围内观察到与共轭聚合物主链的吸收相对应的特征棉花效应，表明聚合物具有由共价键合的二萘基单元诱导的多余单螺旋感的螺旋结构。带有非手性客体的2a-c的主客体络合作用产生了基于主链构象波动的热学变化。络合诱导的热效应变化的行为本质上是由双冠醚单元的空腔大小决定的。此外，在与手性客体络合的情况下，观察到手性响应的螺旋度变化，这也取决于冠醚的大小。
Diacetylene monomers with respective lengths of the oxyethylene chains were cyclopolymerized with a rhodium catalyst to produce novel poly(phenylacetylene)s bearing a different cavity size of the chiral crown ether in the repeating units (2a-c). In the circular dichroism spectra of the resulting polymers, characteristic Cotton effects were observed in the range from 350 to 500 nm corresponding to the absorption of the conjugated polymer backbone, indicating that the polymers possessed a helical structure with an excess single screw sense induced by the covalently bonded binaphthyl units. The host-guest complexation of 2a-c with achiral guests produced a chiroptical change based on the fluctuation in the main chain conformation. The behavior of the complexation-induced chiroptical change was essentially dictated by the cavity size of the binaphthocrown ether units. Additionally, a chirality-responsive helicity change was observed in the case of the complexation of 2a-c with chiral guests, which also depended on the crown ether size.