非对称结构分子基无机杂化非线性光学材料的分子设计、性能与机理研究

The Nonlinear optical materials have a great application prospect in optical information processing, optical computing, optical communication, environmental monitoring and biological imaging, diagnosis and treatment and separation, catalysis, sensors owing to their many particular advantages including well nonlinear optical activity, fast response et al. According to application requirements and the existing problems to develop molecular hybrid nonlinear optical materials with high nonlinear chromophores, orderly evenly dispersion and efficient assembly, and balance challenge of thermal stability and processing performance in a molecular hybrid nonlinear optical materials, in the project, "nonlinear optical theory" and "molecular engineering and molecular design theory" have been adopted to design molecular hybrid nonlinear optical materials with large nonlinear optical susceptibility, orderly evenly dispersed high nonlinear chromophores, and well assembly performance. The unique molecular structural nanosized inorganic polyhedral silsesquioxane (POSS) was applied as blocking platform molecules to improve the thermal stability and processing performance of resulting hybrid materials. The Chemically covalent incorporation between nanosized inorganic polyhedral silsesquioxane (POSS) and organic chromophore & Organic ligand chromophores efficiently overcome the difficulty of high nonlinear chromophores and orderly evenly dispersion. Long arm hydrogen bonding molecular chain will efficiently improve the molecular assembly and processing performance. The researches will importantly focus on control preparation of hybrid material molecules and the relationship between molecular structure and their properties. The enhancement effect and mechanism of POSS nanoparticles on optical nonlinear propertties will be explored by the theoretical simulation of molecular geometrical character and arrangement conducted under the gaussian 06 software suite with B3LYP/6-31G level of theory combining with experimental research of optical properties. The nonlinear optical properties and mechanism of resulting hybrids will be investigated by nonlinear optical measurement system and time-resolved pum-probe technology. Their applications in film device and biology will be expolred.

非线性光学材料具有非线性光学活性高、响应快等优点,在光学信息处理、光计算、光通信、环境监测和生物影像、诊断与治疗以及分离、催化、传感等领域有着巨大的应用前景。针对应用要求以及分子基杂化非线性光学材料中高生色团浓度、均匀有序分散和组装的困难，分子基非线性光学材料热稳定性和加工性能难以兼顾的难题,本课题运用“非线性光学理论”和“分子工程与设计理论”，提出以纳米大小笼型倍半硅氧烷为基础，有机非线性光学和金属有机功能基团为生色团，通过共价连接获得分布均匀、NLO生色团含量高的非对称结构分子基无机杂化复合材料的设计和制备思路，探索和研究材料分子的制备方法、分子结构与性能之间关系。采用量子化学理论中的密度泛函理论，以及Z扫描技术、4f单光束非线性测试技术以及飞秒泵浦探测和微区光谱技术有机结合起来,系统研究体系的光学非线性和超快动力学机理，并探讨其在薄膜器件与生物中的应用性能。

设计新型的非线性光学材料，拓展其应用具有重要的理论意义和应用价值。以纳米POSS作为分子构筑平台，用推拉电子结构的非线性光学生色团作为发光基团，采用点击化学制备方法，通过工艺和组合化学优化，精确控制制备了纳米杂化非对称结构单分子白光发光材料。非对称和杂化结构的设计，有效改善了材料的加工性能和热稳定性；通过分子内能量转移机理，有效减少能量损耗，独特结构纳米POSS的引入，有效地克服了分子聚集效应，两者协同作用实现材料薄膜高效发光。. 采用激光防护性能较好的芳基方酸近红外吸收生色团，以纳米POSS作为分子构筑平台，设计制备出了二个系列（油溶性、水溶性）可见-近红外宽波段吸收非对称结构非线性光学材料。该系列材料具有波段可调、光稳定性好、耐热性强以及具有很好的成膜性等特点，并探究了其太阳能电池领域的应用。研究发现：(1)纳米POSS的引入不仅改善了材料的耐热性和光学稳定性，并且增强了太阳能电池的稳定性和使用寿命；(2)POSS基杂化材料分子呈现出的抗聚集效应和宽波段吸收性能，增强了太阳能电池的光电转化效率。. 使用具有较好近红外激光防护性能的单层石墨烯作为材料的构筑平台，利用设计合成的不同光学生色团分子作为组装体，采用四种不同材料组装方法，分别制备出“Pb2+电化学传感”、“Cu2+荧光传感”、“Cu2+中毒的生物影像分析”和“有机溶剂和食品中痕量水的高灵敏检测”非对称结构传感器材料和器件。该系列材料性能稳定，易于保存和重复使用。. 使用生物基荧光素和罗丹明光学生色基团、量化计算及探针分子设计理论，分别提出了五种不同的材料分子设计方法，制备出了多种非对称结构的新型探针分子，分别实现了重金属离子在环境与生物中的 “多模式”、“多通道”等高灵敏高选择性检测。采用点击化学制备方法，将上述设计的探针分子连接到独特结构的POSS中，构筑的POSS基非对称结构杂化探针材料，同时具有稳定性好，生物检测灵敏性高等特点。