吡啶噁唑啉类配体构筑的自旋交叉配合物：结构设计和功能调控

Spin-crossover (SCO) complexes belong to a type of representative bistable compounds whose electronic states of metal ions can be reversibly switched between high-spin (HS) and low-spin (LS) states via external perturbations. In this project, we propose designing organic ligands based on pyridine-oxazole moieties and constructing mono- and multi-nuclear complexes as well as coordination polymers bearing different dimensional topologies. We will study their spin-crossover and photomagnetic behaviors in depth and explore the potential applications in spin-mediated micro/nano switching devices. Detailed studies with six aspects are performed. First, series of pyridine-oxazole and pyridine-dioxazole mononuclear complexes will be designed and synthesized. The influence to SCO properties by the ligand structures, counter anions, and solvents will be investigated. Second, molecular grids and cages will be constructed that are based on linear and triangular ligands. The modulation of SCO behaviors through magnetic interaction of metal ions or guest molecules will be explored. Third, one to three dimensional coordination polymers will be synthesized using ditopic and multi-topic ligands. Fourth, we will introduce fluorescent group into these SCO complexes and study the synergy between SCO and fluorescence. Fifth, micro/nano switching devices will be prepared according to the modulation of spin states by temperature and light to these SCO complexes. Finally, the electrochromism properties of these SCO complexes will be investigated towards the achievement of multi-functional materials.

自旋交叉配合物在外界的扰动下可以发生金属离子高低自旋态的可逆转变，是一类典型的双稳态化合物。本项目提出基于吡啶噁唑啉单元设计配体，通过与Fe(II)离子或其它过渡金属离子配位构筑单核、多核及不同维度的配位聚合物，深入研究其自旋交叉和光磁行为，并探索该类化合物在自旋调控微纳器件中的潜在应用。具体的研究内容包括以下六个方面：合成系列吡啶双噁唑啉和吡啶单噁唑啉单核配合物，研究配体结构、抗衡离子和溶剂对自旋交叉行为的影响；设计直线形和三角形配体构筑栅栏型和笼状多核配合物，考察金属离子中心磁相互作用以及客体分子对于自旋交叉行为的影响；设计扩展型双头基和多头基配体构筑的一维、二维和三维自旋交叉配位聚合物；在自旋交叉配合物中引入荧光基团，研究荧光与自旋交叉之间的协同作用；利用温度和光对自旋交叉配合物自旋态的调控制备微纳开关器件；考察该类配合物的电致变色性质，发展自旋交叉和电致变色复合的多功能配合物。