Nagai Kanji, Maeda Katsuhiro, Takeyama Yoshihisa, Sato Takahiro, Yashima Eiji
Department of Molecular Design and Engineering, Graduate School of Engineering, Nagoya University, Chikusa-ku, Nagoya 464-8603, Japan.
Chem Asian J. 2007 Oct 1;2(10):1314-21. doi: 10.1002/asia.200700185.
A stereoregular poly(phenylacetylene) bearing an N,N-diisopropylaminomethyl group as the pendant (poly-1) changed its structure into the prevailing one-handed helical conformation upon complexation with optically active acids in water. The complexes exhibited induced circular dichroism (ICD) in the UV/Vis region of the polymer backbone. Poly-1 is highly sensitive to the chirality of chiral acids and can detect a small enantiomeric imbalance in these acids, in particular, phenyl lactic acid in water. For example, a 0.005% enantiomeric excess of phenyl lactic acid can be detected by CD spectroscopy. The observed ICD intensity and pattern of poly-1 were dependent on the temperature and concentration of poly-1, probably due to aggregations of the polymer at high temperature as revealed by dynamic light scattering and AFM. On the basis of the temperature-dependent ICD changes, the preferred chiral helical sense of poly-1 was found to be controlled by noncovalent bonding interactions by using structurally different enantiomeric acids.
一种带有N,N-二异丙基氨基甲基作为侧基的立构规整聚乙炔（聚-1），在水中与旋光酸络合时，其结构转变为占主导的单手螺旋构象。这些络合物在聚合物主链的紫外/可见区域表现出诱导圆二色性（ICD）。聚-1对手性酸的手性高度敏感，能够检测这些酸中的微小对映体失衡，特别是水中的苯基乳酸。例如，通过圆二色光谱可以检测到0.005%的苯基乳酸对映体过量。观察到的聚-1的ICD强度和模式取决于聚-1的温度和浓度，这可能是由于动态光散射和原子力显微镜揭示的高温下聚合物的聚集。基于温度依赖性的ICD变化，通过使用结构不同的对映体酸，发现聚-1的优选手性螺旋方向由非共价键相互作用控制。
