A new 2D network constructed by polymeric anions and lanthanides. Synthesis, structure and magnetic property of two new compounds

Two new compounds based on [H2W12O40]6− (W12) clusters and Ln-organic complexes, [Ln3(Hdipic)(dipic)(H2O)13(H2W12O40)]·13H2O Ln = Sm (1), Gd (2), (dipic = pyridine-2,6-dicarboxylate anion) have been synthesized and characterized by element analysis, IR spectrometry and thermogravimetric analysis. Single-crystal X-ray diffraction analyses reveal that compounds and are isostructural. In and four Ln3+ ions lie in a plane and form a centrosymmetric regular rhomblike ring {Ln4(dipic)2(Hdipic)2(H2O)12}6+(Sm4-ring) through the ligands. The covalent combination of W12 subunits as a tetradentate ligand to Ln4-rings from two sides creates a polymeric anion, {[H2W12O40]2[Ln4(dipic)2(Hdipic)2(H2O)12]}6−, and then Ln1 ions connect these anions leading to the 2D layers. The magnetic measurements indicate that in and there exist very weak antiferromagnetic interactions.