卤素离子触发亚铁四面体笼的自旋状态转换（英文）

Halide Triggered Spin State Switching of Iron(Ⅱ) Tetrahedral Cages

合理构筑了3个具有固态自旋交叉特性的亚铁四面体笼状化合物1~3。单晶X射线衍射分析证实了化合物是由6个咪唑席夫碱配体和4个亚铁离子组装形成的边导向封顶胶囊结构。金属中心占据四面体的顶点,而配体组成了四面体的边。这些笼状化合物的内部空腔被咪唑基团环绕,而外部则被取代苯环包围。一个阴离子客体被限域在笼状化合物空腔内,并与笼状化合物主体产生较强的相互作用。当在笼状化合物的乙腈溶液中加入卤素离子(Cl^-和Br^-)时,溶液的颜色和MLCT峰强度会发生明显变化,表明亚铁四面体笼状化合物的自旋状态由低自旋向髙自旋发生了转换。

Three iron(Ⅱ)tetrahedral cages 1~3 with solid state spin-crossover properties were rational constructed.Single crystal X-ray diffraction analysis confirmed the edge-capped capsule,which were assembled from six imidazole Schiff-base ligands and four iron(Ⅱ)ions.The metal centers occupy the vertices and each linker situates at the edges of the tetrahedron.The inner cavities of these cages are surrounded by imidazole groups,while the periphery is decorated by substituted phenyl rings.One of the counter anions is encapsulated at the central cavities and shows strong anion binding interactions with the cages.Interestingly,the iron(Ⅱ)cages in solution can change their spin states from low-spin(LS)to high-spin(HS)upon addition of halide,since tremendous change of solution color and absorption intensity of characteristic broad absorption MLCT bands when addition of halide(Cl-and Br-)to the CH3CN solution of the cages.CCDC:1560377,1;1560378,2;1560379,3.