Coordination Architectures of Lanthanum Complexes Based on Bifunctional 5-Substituted Tetrazolecarboxylate Ligands

Three complexes of bifunctional 5-substituted tetrazolatecarboxylate ligands [2-(5-(pyrazin-2-yl)-2H-tetrazol-2-yl)acetic acid (Hpztza), 3-(5-amino-2H-tetrazol-1(5H)-yl)propanoic acid (Hatzp), and N,N′-bis(tetrazol-5-yl)anime-N2,N2′-diacetic acid (H2datza)], namely a mononuclear structure [La(pztza)2(H2O)5]·4H2O·pztza (1), a 1D polymeric chain structure [La2(atzp)4(H2O)8]·2NO3·2H2O (2), and a 2D layer network [La(datza)(H2O)3]·4H2O (3) were prepared and structurally characterized by elemental analysis, IR spectroscopy, and single-crystal X-ray diffraction. The structures of these complexes are controlled not only by the number and different coordination modes of the tetrazole-carboxylate ligands but also the different 5-substituents of the tetrazole ring. The complexes show ligand-centered luminescence at room temperature in the solid state. The obvious enhancements in luminescence make these complexes to be the potential materials for optical use.