多烯烃金属配合物的设计合成及其多重开关环反应和性质的研究

设计合成多重光开关分子可为制造多频可控记忆及数据存储器件材料提供可能，该领域已成为新的化学和材料研究热点。C=C双键间的[2＋2]环加成及其开环反应是光允许、热禁阻的反应，含多个双键化合物可以实现多步环加成与开环，因此，是一种潜在的、热稳定的光学信息存储材料。本项目拟设计合成含多烯键吡啶基等含氮杂环有机配体或羧酸配体，通过它们与金属离子进行溶液反应或溶剂热反应，得到C=C双键平行排列的配合物。在不同波长的光照射下，分步形成四元环产物；选择合适的光或温度对四元环产物照射或加热，使其中形成的四元环逐步开环。探索这些开关环反应机理以及入射光波长、加热温度等对关环和开环反应的影响，测定多步形成的四元环产物或由其多步开环的不同状态下的紫外吸收、荧光、导电、介电等性质变化，筛选出对光响应优良的配合物制备成相关的信息存储器件。

Multiple photoswitchable molecules provide a promise for the preparation of multi-frequency controllable memory and data storage device materials and become a hot research topic in chemistry and material science. The traditional [2+2] cyclo-addition between the two olefinic bonds is theoretically photo-permitted while its cyclo-elimination is thermo-prohibited. Those containing multi-olefin bonds can be designed and controlled to proceed stepwise cyclo-addition and cyclo-elimination in solid state. Such a reversible process denotes these compounds as a promising thermo-stable optical information storage materials. This project is planned to design and prepare pyridyl-based ligands with multi-olefin bonds and other nitrogen-containing heterocyclic ligands or carboxylic acid ligands with multi-olefin bonds. The reactions of these ligands with metal ions under solvothermal conditions are carried out to produce various coordination compounds with different arrangements of C=C pairs. Upon UV light irradiation with different wavelengths, each C=C pair in the structures of these compounds is cyclodimerized. On the other hand, the resulting cyclobutane ring is gradually cleaved through irradiation of UV light with shorter wavelengths or by heating at a suitable temperature. We will explore the mechanisms and effects of irradiation wavelengths, heating temperatures on these ring-open and ring-closure reactions. More importantly, we will determine and measure various physical responses originated from such multiple ring-open and ring-closure reactions. Observation and measurement of the UV absorption, photoluminescence, conductivity and dielectric responses are our main interests in this project. Finally, we will screen out some compounds with excellent photo-responses to prepare potential data and information storage devices.