Jing Huiru, Dan Wenyan, Zhu Jiaxing, Ling Yun, Jia Yu, Yang Yongtai, Liu Xiaofeng, Chen Zhenxia, Zhou Yaming
Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Department of Chemistry, Fudan University, Shanghai 200438, China.
College of Chemical Science and Engineering, Tongji University, Shanghai 200092, China.
Dalton Trans. 2021 Jun 1;50(21):7380-7387. doi: 10.1039/d1dt01052b.
A series of isostructural lanthanide phosphonocarboxylate frameworks {(H3O)3[Ln7(pbpdc)6(DMF)4(H2O)3]·4H2O}n (named LnPCF, Ln = Tb, Eu and Gd, H4pbpdc = 4'-phosphono-[1,1'-biphenyl]-3,5-dicarboxylic acid) were solvothermally synthesized and characterized by the single crystal X-ray diffraction technique. By combining lanthanide cations with a phosphonocarboxylate ligand, a heptametallic lanthanide phosphonate [Ln7(PO3)6(COO)12] core was obtained. This core exhibited as a rare highly 18-connected node and was linked by the 3-connected pbpdc4- ligand, forming a (3,18)-connected framework with a novel topology of {43}6{438·676·839}. This LnPCF structure is an ideal platform for accommodating various lanthanide ions. The TbPCF and EuPCF show efficient luminescence emission due to the "antenna effect" and incorporating Gd3+ into the TbPCF results in a drastic luminescence enhancement. Fine colour tuning between green and red can be easily achieved in bimetallic TbxGd1-xPCFs. More significantly, upon combining a few percent of Nd3+ and Gd3+ with Tb3+, the resulting trimetallic Tb0.4Gd0.5Nd0.1PCF shows dual emissions of both visible and near-infrared light.
通过溶剂热法合成了一系列同构的镧系膦酰基羧酸盐框架{(H3O)3[Ln7(pbpdc)6(DMF)4(H2O)3]·4H2O}n（命名为LnPCF，Ln = Tb、Eu和Gd，H4pbpdc = 4'-膦酰基-[1,1'-联苯]-3,5-二羧酸），并通过单晶X射线衍射技术对其进行了表征。通过将镧系阳离子与膦酰基羧酸盐配体结合，得到了一个七金属镧系膦酸盐[Ln7(PO3)6(COO)12]核。该核表现为一种罕见的高度18连接节点，并通过3连接的pbpdc4-配体连接，形成了具有{43}6{438·676·839}新颖拓扑结构的(3,18)连接框架。这种LnPCF结构是容纳各种镧系离子的理想平台。由于“天线效应”，TbPCF和EuPCF表现出高效的发光发射，并且将Gd3+掺入TbPCF中会导致发光显著增强。在双金属TbxGd1-xPCFs中可以轻松实现绿色和红色之间的精细颜色调节。更重要的是，当将百分之几的Nd3+和Gd3+与Tb3+结合时，所得的三金属Tb0.4Gd0.5Nd0.1PCF显示出可见光和近红外光的双重发射。
