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.