New coordination polymers of lanthanide(III) with tetrazole-1-acetic acid: Synthesis, crystal structures, and magnetic properties

New coordination polymers {[Ln(tza)(3)(H2O)(2)] center dot mH(2)O}(n) (Ln = La-III 1 and Pr-III 2, m = 2; Ln = Nd-III 3, m = 1.5) and {[Sm-2(tza)(6)(H2O)(5)] center dot H2O}(n) 4 ( Htza = tetrazole-1-acetic acid) have been synthesized and characterized by IR spectroscopy, elemental analysis, X-ray crystallography, and magnetic measurements. The Htza ligand coordinates to the lanthanide cations through the carboxylate group in a monodentate, bridging bidentate coordination mode or bridging tridentate to two metal centres. Complexes 1 and 2 are isostructural. Complex 3 has a similar structure to 1 and 2, but the arrangement of ligands has changed. Complex 4 consists of two types of metallic molecules. Magnetic measurements show weak antiferromagnetic coupling between the metal centres in complexes 2 and 3.