自旋交叉纳米材料的自组装制备及其性能研究

Nowadays, the research on molecular electronic devices has been an important interdisciplinary of chemistry, physics and materials sciences. The spin crossover complexes are the ideal material to fabricate molecular electronic devices, since the bistable switching between two electronic states of spin crossover complexes can be repeated without attenuation. Thus, scientists are always seeking the innovative techniques with extensive applicability for the preparation of spin crossover nanomaterial. The project puts forward a novel method based on self-assembly to fabricate excellent spin crossover nanomaterial with controlled size and morphology and free of organic coating. The idea of molecular design is to endow spin crossover complexes with self-assembly ability by introducing self-assembly groups and to enhance the intermolecular non-covalent interactions by modifying the molecular linker to improve the spin crossover cooperativity. Moreover, the molecular assembly mechanism will be discussed through the analysis of the physical and chemical properties of spin crossover nanomaterial. Then, the influence of the size and morphology effects on the transition temperature and width of the hysteresis loop of spin crossover nanomaterial will also be systematically studied for further exploring the potential applications in the fields of sensing and information storage.

分子级别电子器件的研究已经发展成为物理、化学和材料学科的重要交叉研究领域。自旋交叉配合物的双稳态之间的转换可按需重复且不会出现疲劳现象，是制备电子器件的理想材料。因此，科学家们一直寻求新颖且应用广泛的制备自旋交叉纳米材料的方法和技术。本项目提出基于自组装的分子凝胶技术制备无表面包覆、形貌及尺寸可控且性能优异的自旋交叉纳米材料。在自旋交叉配合物分子结构设计中引入自组装结构单元，使得分子具有自组装性能；并对配体的连接臂进行修饰，增加分子间非共价键相互作用，提高纳米材料的自旋交叉协同性。通过对自旋交叉纳米材料理化性质的表征，研究该类自旋交叉配合物分子的组装机理。进一步研究纳米材料的形貌、尺寸效应对自旋转换温度和回滞曲线宽度的影响，从而设计制备性能优异的自旋交叉纳米材料，并探索其在传感、信息存储等领域的应用。

信息爆炸以及电子器件微型化的时代亟需研发新型记忆材料，自旋交叉（SCO）材料可以在分子的两种电子态，即高自旋（HS）和低自旋（LS）态之间进行切换，因此被认为是最有前景的材料之一。然而，可控制备无包覆的SCO纳米材料仍然是一个巨大的挑战。基于此，本项目通过超分子凝胶策略来制备新型SCO纳米材料。通过改变组装的浓度、溶剂和温度，可以制备出具有不同尺寸、形貌，且无表面活性剂/聚合物包覆的SCO纳米材料。进一步通过光学和磁性测量来研究其自旋交叉行为，发现立方形纳米材料的自旋转换在室温且伴有12 K的回滞宽度，使其有望应用于存储器件、显示器件、无墨打印和微机电系统。相关研究成果发表SCI论文3篇，申请国家发明专利2项。