New Lanthanide Hybrid as Clustered Infinite Nanotunnel with 3D Ln−O−Ln Framework and (3,4)-Connected Net

A series of new lanthanide hybrids [Ln3(μ-OH)4 (2,5-pydc)(2,5-Hpydc)3(H2O)4]n (Ln = Gd (1), Dy (2), Er (3), Eu (4),
Sm (5), Yb (6), Y (7); 2,5-pydc=pyridine-2,5-dicarboxylate), as clustered lanthanide oxide ring tunnels with helical
dodecahedral chains and fully 3D Ln−O−Ln connectivity, has been hydrothermally synthesized and characterized.
The inorganic skeleton of the hybrid can be specified by the Schläfli symbol (6210)2 (64102) as a single 3D (3,4)-connected net. The luminescence properties have been studied, and the results showed that the Dy(III) (2) and
Eu(III) (4) complexes exhibited sensitized luminescence in the visible region. Variable-temperature magnetic
susceptibility measurements of 1−6 showed that the complexes 1−3 are nearly paramagnets, whereas the
depopulation of the Stark levels in complexes 4−6 leads to a continuous decrease in μeff when the sample is
cooled from 300 to 2 K.

一系列新型镧系杂化物[Ln₃(μ-桥联羟基)₄(2,5-pydc)(2,5-Hpydc)₃(H₂O)₄]ₙ（其中Ln=Gd(1)、Dy(2)、Er(3)、Eu(4)、Sm(5)、Yb(6)、Y(7)；2,5-pydc=吡啶-2,5-二羧酸根（pyridine-2,5-dicarboxylate）），具备螺旋型十二面体链结构的簇状镧系氧化物环隧道与全三维Ln-O-Ln连接骨架，通过水热法合成并完成了结构表征。该杂化物的无机骨架可通过施莱夫利符号（Schläfli symbol）(6²10)₂(6⁴10₂)定义为单一的三维(3,4)-连接网格。对其发光性能开展了研究，结果显示配合物2（Dy(III)）与4（Eu(III)）在可见光区域表现出敏化发光特性。针对配合物1~6的变温磁化率测试表明，配合物1~3近乎呈现顺磁性；而配合物4~6的斯塔克能级（Stark levels）布居数随温度从300K降至2K时逐渐减少，导致有效磁矩（μeff）持续下降。