【作者】 吴兵；

【导师】 章于川；

【作者基本信息】 安徽大学 ， 应用化学， 2007， 硕士

【摘要】 本论文根据液晶分子结构理论，以对溴苯酚、反式溴代烷基环己烷、(-)-2-甲基丁醇、对羟基苯甲酸甲酯等为原料，通过偶联、醚化、酯化等反应合成了两种新型的手性液晶化合物；以(-)-2-辛醇为手性基团合成了液晶手性掺杂剂S811，并将所合成的手性剂与一种宽温域型TN混晶混合，研究了手性剂的加入量对混晶各种电光特性的影响。通过熔点、红外、核磁等测试对所合成的化合物进行了表征，并用HPLC检测了两种手性液晶化合物的纯度；应用DSC、TPOM、XRD对两种手性液晶的性质进行了研究；应用液晶性能综合测定仪研究了S811和TN混晶混合物的电光特性。主要工作内容如下：1、总结了铁电性液晶和胆甾相液晶的基本理论与应用前景，并依据手性液晶分子理论结构，设计、合成了两种以(-)-2-甲基丁醇为手性中心的酯类液晶化合物，比较了几种常用的酯化反应方法，讨论了实验的影响因素，优化选择了最佳合成路线和合成条件。2、运用DSC、TPOM、XRD对两种手性液晶化合物的液晶性进行了表征。采用Chem.3D中的MM2模板程序，应用计算机模拟计算出分子链处于能量最低、最优构象时的分子长度，并结合XRD结果对化合物的液晶相态与相变进行了合理的分析。3、采用了较为合适的路线合成了液晶手性掺杂剂S811，对合成过程中选用的DCC／DMAP催化酯化法进行了研究和讨论。4、将S811按照不同的比例加入到TiN混晶中，测试了手性掺杂剂浓度对混晶阈值电压、阈值陡度、上升时间、下降时间、对比度、视角等重要电光性能的影响。更多还原

【Abstract】 Based on the liquid crystal molecules theory, two kinds of chiral liquid crystal compounds were synthesized by choosing p-bromophenol、trans-n-alkylcyclohexane Bromide、(-)-2-methyulbutanol、methyl p-hydroxylbenzoate as primary materials through the reactions of coupling、etherification、esterification et al; An important chiral dopant S811 was synthesized by choosing (-)-2-octanol as chiral group. Mixture was made of the dopant and wide-temperature range TN mixed liquidcrystals: studied the dependence of electro-optical properties of TN mixed liquidcrystals on capacitance of chiral dopant.The structure of intermediates and terminal materials was identified by Meltingpoint、FTIR、~1HNMR et al. The purity of two kinds ofchiral liquid crystal compounds was detected by HPLC; their properties of liquid crystal crystalline were characterized by Differential Scanning Calorimeter(DSC)、Thermal Polarized Optical Microscope(TPOM) and X-ray Diffraction(XRD). The Instrument of Determining Comprehensive Parameters LCD-5016C studied the electro-optical properties of the mixture.The main points of this dissertion consist the following points:1. Basic theory and application prospects of ferroelectric liquid crystal and cholesteric liquid crystal were summarized, according to Ferroelectric liquid crystal molecular structure theory, two kinds of ester liquid crystal coumpounds were designed and synthesized by choosing (-)-2-methyulbutanol as chiral center. Some of the more common routes of esterification were compared, the experimental factors were discussed, and optimal synthetic route was selected.2. The liquid crystalline properties of two chiral liquid crystal compounds Were characterized by using DSC、TPOM、XRD. The length of molecule was analog by using Chem.3D MM2 template when it was at the lowest energy chain with optimal conformation. And reasonable explanation of the liquid crystal phase was given according to the X-ray diffraction results.3. Adopted a more suitable routes in the synthesis of LCD chiral dopant S811, the DCC/DMAP catalytic esterification method was conducted a study and discussion.4. Mixture was made of the dopant and wide-temperature range TN mixed liquidcrystals, the dependence of electro-optical properties such as threshold voltage、threshold steep、rise time、fall time、contrast、viewing angle of TN mixed liquidcrystals on capacitance of chiral dopant was studied.更多还原