Two Supramolecular Inorganic–Organic Hybrids of 12‐Silicotungstic Acid Heteropolyoxometalate and Trinuclear Lanthanide Clusters: Syntheses, Structures, and Magnetic Properties

Abstract Hydrothermal synthesis of two novel inorganic–organic hybrid assemblies, {Na[Ln(pydc‐OH)(H 2 O) 4 ] 3 }[SiW 12 O 40 ] · 15H 2 O [Ln = Nd ( 1 ) and Ln = Sm, ( 2 ); pydc‐OH = 4‐hydroxypyridine‐2,6‐dicarboxy], and their characterization is described. Structural characterizations by single‐crystal X‐ray diffraction reveal that these compounds are isostructural, and each consists of [SiW 12 O 40 ] 4– Keggin‐type polyoxometalates (POMs) linked by three lanthanide ions to yield discrete trinuclear lanthanide clusters. These discrete molecules are further packed into 3D supramolecular assemblies by means of hydrogen‐bonding and anion–π interactions. Both compounds exhibit remarkable thermal stability. The temperature variation in the magnetic susceptibility χ m and of the χ m T product and Bohr magnetons of the Nd III ( 1 )‐ and Sm III ( 2 )‐based compounds are considered. The magnetic data have been interpreted relative to data presented in the literature.