DEVELOPMENT OF NEW ORGANIC NONLINEAR OPTICAL MATERIELS

这项研究是为了从新设计的具有长和极性杂环生色团的化合物中制备光学非线性有机薄膜。本研究取得的重要成果如下：1.利用Langmuir-Blodgett(LB)技术研究了含苯并吡嗪或苯并吡嗪生色基团的两亲分子是制备有机薄膜的优良两亲性分子。与相关化合物的比较表明，吡嗪和哒嗪类化合物的优异性能可能是由于层状结构中这些杂环之间的静电多极-多极相互作用造成的。这一考虑被基于二维晶体模型的计算机模拟所支持。利用扫描隧道显微镜(STM)可以观察到烷氧基苯基吡嗪碳腈液晶材料单分子膜中的分子排列，并通过同样的模拟再现了STM图像，这表明该模拟可以作为化合物分子设计以制备分子组装的指导思想。通过在含吡嗪环的两亲分子的疏水烷基链末端引入丙烯氧基，得到了Z型LB膜。光聚合机械增强的Z型LB膜表现出较强的二次谐波产生。烷基末端含有MeO-、NC-、N_3-的两亲分子也形成了Z型LB膜，这表明烷基末端引入极性基团会导致Z型沉积，有利于单线光学活性。还制备了两个芳香环之间具有乙酰键或二乙烯键的两亲分子。这些化合物的LB膜是一种强非线性光学材料

This investigation was performed to develop optically non-linear organic thin films from newly designed compounds having long and polar heterocyclic chromophores. The important results obtained by this study are as follow :1. The amphiphiles having phenylpyrazine or phenylpyridazine chromophore were shown to be excellent amphiphiles to fabricate organic thin film by Langmuir-Blodgett (LB) technique. Comparison with related compounds suggested the excellence of pyrazine and pyridazine derivatives would be caused by electrostatic multipole-multipole interaction between these heterocycles in the layred structures. This consideration was supported by computer simulation based on 2-dimensional crystalline models. The molecular arrangement in the monolayr of a liquid crystalline material, alkoxyphenylpyrazine carbonitrile, could be observed by scanning tunneling microscope (STM) and the STM image was reproduced by same simulation, which revealed this simulation could be used as a guide line for the molecular design of compound to fabricate molecular assemblies.2. By introduction of acryloxy group at the end of the hydrophobic alkyl chain of an amphiphile having pyrazine ring, Z-type LB film was obtained. The Z-type LB film mechanically strengthened by photopolymerization showed strong second harmonic generation. The amphiphiles having MeO-, NC-, N_3- at the end of alkyl group also gave Z-type LB film, which revealed that introducing polar group at the end of alkyl chain caused Z-type deposition which is favorable for monlinear optical activity.3. Amphiphiles having acetylenic or diacetylenic linkage between two aromatic rings were also prepared. The LB-films of these compound were shown to be strong nonlinear optical material