【摘要】 采用分步组装策略,利用3-位和4-位吡啶端基化的三脚配体,合成了分立的单核Ln(Ln=Tb/Sm/Yb)配合物,进一步通过吡啶端基的配位扩展,分别组装得到不同拓扑的Ln-M(M=Ag或Cd)三维金属-有机框架(MOF)结构。异核MOF保留了Ln配位中心的特征可见至近红外发光,并因配体能级结构和与稀土离子间的能量传递效率的改变,对配合物的发光性能产生调控。其中配合物2-Yb-Ag中,Yb的近红外发光与单核稀土配合物相比明显增强,荧光寿命从单核的4.3μs增加到6.7μs,而4-Tb-Cd则产生了配体发光与稀土中心发光的组合模式,其中来自Tb中心的荧光寿命从相应单核配合物中的2.91 ms缩短至0.62 ms。更多还原

【Abstract】 Via stepwise assembly method,discrete mononuclear Ln（ Ln = Tb/Sm/Yb） complexes were synthesized from 3-or 4-pyridyl modified tripodal ligands,which were then assembled into three dimensional Ln-M（ M = Ag or Cd） metal-organic frameworks（ MOFs） with different topologies through the linkage of pyridyl ends. The heteronuclear MOFs sustain a characteristic emission of Ln³⁺coordination centers,but the energy levels of the ligands are lowered in the three-dimensional packing structures,which affects the energy transfer efficiency to lanthanide centers. As a result,a stronger near-infrared luminescence is obtained in 2-Yb-Ag compared with its mononuclear counterpart,and the decay lifetime increases from 4. 3 μs to 6. 7 μs.While 4-Tb-Cd simultaneously emits metal-centered and ligand-based emissions,in which the decay lifetime for Tb-centered emission shortens from 2. 91 ms to 0. 62 ms compared with the corresponding mononuclear complex.更多还原