Ligand-Assisted Assembly of a Family of 3d-4f Cluster-Templated Ln-Polyoxoniobate Cages with a Nested
Bi-He Lin1, Yu-Diao Lin2, Shou-Tian Zheng1
1Fujian Provincial Key Laboratory of Advanced Inorganic Oxygenated Materials, College of Chemistry, Fuzhou University, Fuzhou, Fujian 350108, China.
Abstract:
A flexible organic ligand-assisted strategy was developed to incorporate lanthanide ions into polyoxoniobate frameworks, yielding a series of Ln-containing polyoxoniobate cages (Ln-PONb cages 1-Ln) stabilized by 3d-4f heterometallic clusters. Compounds 1-Ln feature a giant anionic Ln4Nb96 supercage with an internal Ln4Nb24 cluster displaying a rare fullerene-like topology. These supercages assemble with propeller-like {LnCu4(H4L)4}3+ cations via electrostatic interactions to form three-dimensional frameworks. Magnetic studies of 1-Ln (Ln = La, Ce, Pr, Nd) reveal that the magnetic behavior is strongly Ln3+-dependent: 1-Ce and 1-Nd exhibit dominant antiferromagnetic coupling, while 1-La and 1-Pr show ferromagnetic coupling. This work provides a promising strategy for constructing POM-based cage materials with unique topologies and tunable magnetic properties.
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