Helicity Induction of Polymers in Water and Its Memory

近年来，具有可控螺旋方向的螺旋聚合物由于其独特的结构和在材料科学中的潜在应用而引起了人们极大的兴趣。最近，我们发现，主要是单手螺旋的大分子螺旋性可以诱导在光学非活性的聚（苯乙炔）轴承各种功能团后，在DMSO中与手性胺络合，从而表现出诱导的圆二色性（ICD）的聚合物主链。此外，用非手性胺取代手性胺后，可以进一步记忆诱导的螺旋结构。在本研究中，我们利用红外光谱、紫外光谱和圆二色光谱研究了水和有机溶剂中的螺旋诱导和螺旋手性记忆。我们发现，在水溶液中，小分子手性客体诱导的带电聚苯乙炔的大分子螺旋性可以通过非手性聚电解质的交替沉积而保持。 ...更多信息 具有相反电荷，导致具有大分子螺旋度记忆的光学活性多层薄膜。这可能是一种由水诱导的螺旋聚合物所产生的螺旋性记忆.我们还证明了在大分子和随后的超分子介观水平上，手性信息从非外消旋客体到螺旋体系的传递过程中，手性的一种新的分级放大.主链刚度与动态螺旋带电聚乙炔，允许形成的液晶（LC）相是必不可少的实现这种分层放大的手性系统。在X射线衍射分析的基础上，提出了LC螺旋聚乙炔最合理的螺旋结构为23单位/10圈（23/10）螺旋，并进一步发现了基于温度和溶剂刺激的螺旋度反转，在聚乙炔中诱导的对映体右旋和左旋螺旋构象的双重记忆。聚乙炔折叠成单手螺旋诱导的非共价键相互作用与一个单一的对映体胺。诱导的螺旋通过温度和溶剂进行可逆反转的螺旋度。当光学活性胺被非手性二胺取代时，在不同温度下获得的非对映体右手和左手螺旋可以进一步记忆，从而产生彼此镜像的右手和左手螺旋。少

The design and synthesis of helical polymers with controlled helix-sense have aroused considerable interest in recent years because of their unique structures and their possible applications in materials science. Recently, we found that macromolecular helicity with a predominantly one-handed helix could be induced in optically inactive poly(phenylacetylenes) bearing various functional groups upon complexation with chiral amines in DMSO, thus exhibiting an induced circular dichroism (ICD) in the polymer main chain. Moreover, the induced helical structures could be further memorized after replacement of the chiral amines by achiral amines. In this study, we investigated the helicity induction and the memory of helical chirality in water or in organic solvents by means of IR, UV, and CD spectroscopies. We found that the macromolecular helicity of charged poly(phenylacetylene)s induced by small chiral guests in water could be retained by the alternative deposition of achiral polyelectrolyt … More es with opposite charges, resulting in optically active multilayer thin films with a macromolecular helicity memory. This may be a kind of memory of the helicity resulting from helical polymers induced in water.We also demonstrated a novel hierarchical amplification of chirality during the transfer of chiral information from nonracemic guests to the helical systems either at macromolecular and subsequent supramolecular mesoscopic levels. The main chain stiffness with a dynamic helical charged polyacetylene that allows a formation of the liquid crystal (LC) phase is essential for realizing this hierarchical amplification of the chirality system. On the basis of the X-ray analyses, the most plausible helical structure of the LC helical polyacetylene is proposed to be a 23 unit/10 turn (23/10) helix.We further found the dual memory of both the enantiomeric right- and left-handed helical conformations induced in a polyacetylene based on the temperature-and solvent-stimulated helicity inversion of the polymer. The polyacetylene folds into a one-handed helix induced by noncovalent bonding interactions with a single enantiomeric amine. The induced helix underwent a reversible inversion of the helicity by temperature and solvents. The diastereomeric right- and left-handed helices obtained at different temperatures could be further memorized when the optically active amine was replaced by an achiral diamine, generating right- and left-handed helices of the mirror images from each other. Less