含有芳环侧链的聚硅烷的手性转移和对映体分离

This project aims at studying the chiral transfer and enantioseparation behaviours of the polysilanes with aromatic side chains. Firstly, monomers with aromatic rings will be synthesized. Then, three series of polysilanes will be synthesized through a Wurtz coupling reaction. Secondly, their chiral transfer behaviours will be studied. For the polysilanes with both aromatic rings and achiral alkyl side chains, their molecular recognization mechanism of chiral low-molecular-weight compounds will be studied using circular dichroism spectroscopy and quantum chemistry calculation. Then, they will be grafted on the surface of quartz and used as chirality sensors for low-molecular-weight compounds. For the polysilanes with both aromatic rings and chiral alkyl chains, the relationship between the chirality of the single chain and that of the aggregates will be studied. Moreover, the effect of the distance between the aromatic ring and silicon atom as well as the effect of the position of the subsituent groups of the aromatic rings will be also studied. For the copolymers, the sergeant-soldier effect on the structures of the polysilanes will be studied. Finally, the enantioseparation behaviours of chiral polysilanes will be studied by grafting them on the surface of silica spheres which will be used as the stationary phase for HPLC. This project will give us a better understanding of the chiral transfer behaviours of polysilanes. Moreover, this project will also establish the theoretical and experimental foundations for the applications of the polysilanes.

本项目旨在研究含有芳环侧基的聚硅烷的手性转移性质和对映体拆分能力。首先合成含有芳环的单体，通过武慈偶联得到三个系列的聚硅烷。然后研究其手性转移性质。对于同时含有芳环和非手性侧链的聚硅烷，运用圆二色谱和量化计算研究其在溶液和聚集体状态下对手性小分子识别的机理。并将聚硅烷键合在石英片上，作为手性检测器检测小分子化合物的手性。对于同时含有芳环和手性烷基链的聚硅烷，研究单分子链和聚集体之间的手性关系，芳环侧基与硅原子之间距离以及芳环上取代基的位置对聚硅烷手性的影响。对于手性共聚物，结合圆二色谱和量化计算，研究其军官-士兵效应与高聚物结构之间的关系。最后，通过将手性聚硅烷键合在硅胶球上，研究其对映体拆分能力。该项目的成功实施有利于对聚硅烷的手性传递机理的深入理解。并且也为手性聚硅烷的实际应用奠定理论和实验基础。

本项目旨在研究含有芳环侧基的聚硅烷的手性转移性质和对映体拆分能力。并拓展到双烷基取代聚硅烷。成功合成含了有苯基和联苯基团的二氯硅烷以及双烷基取代二氯硅烷单体，并通过武慈偶联得到了相对分子量在五千至两万的芳基取代聚硅烷，以及相对分子量在十万以内的双烷基取代聚硅烷。其分子量分布在1.1以内。研究成果如下：一、芳环的引入明显提高其耐紫外性能。对于聚硅烷共聚物，其耐紫外辐照的能力随着芳环比例的提高而增强。二、芳基取代聚硅烷可以识别手性醇。羟基和硅之间的相互作用被认为是手性传递的主要驱动力。三、手性芳基取代聚硅烷共聚物可以用来分离芳香化合物以及苯乙醇对映体。其分离的主要作用力可能是π-π相互作用和羟基/硅之间的相互作用。四、涡旋力可以诱导聚硅烷形成优势手性构象，并可诱导手性堆积。其驱动力可能与高分子链局部手性堆积有关。也有可能是由于聚硅烷高分子链左右手转变能量较低。五、胶束中，光学活性和非光学活性聚硅烷手性传递，一个光学活性聚硅烷可以是的3到4个非光学活性聚硅烷转变为单一手性。其手性放大与分子正交堆积有密切关系。六、在光学活性聚硅烷共混物和共聚物中，发现了微观相分离诱导手性放大。七、非光学活性聚硅烷可以用来检测螺旋纳米材料的手性。这些纳米材料包括：单手螺旋碳管、碳化硅管和五氧化二钽管等。本项目不仅仅为地球上单一手性起源提供了一个依据，而且还为其在对映体拆分和手性识别领域的应用奠定了基础。