A New Family of 3d–4f Heterometallic Tetrazole-based Coordination Frameworks: In Situ Tetrazole Ligand Synthesis, Structure, Luminescence, and Magnetic Properties

A series of novel three-dimensional (3D) Ln­(III)–Cu­(I) heterometallic tetrazole-based coordination frameworks, namely, [LnCu­(3-tzba)2(H2O)4] [Ln = Eu (1), Gd (2), Tb (3), Dy (4); 3-tzba = 3-(1H-tetrazol-5-yl)­benzoate], were successfully synthesized through in situ [2 + 3] cycloaddition reaction under hydrothermal conditions. Compounds 1–4 are isostructural 3D coordination frameworks with 1D anionic chains [Ln­(3-tzba)2(H2O)4]− linking the adjacent Cu­(I) ions possessing a uninodal 10-connected topology with the short (Schläfli) vertex symbol of (312.424.59). To the best of our knowledge, they are the first lanthanide–transition heterometal–organic coordination frameworks obtained through in situ tetrazole synthesis. In addition, the luminescence properties of 1 and 3 and the magnetic properties of 2 and 4 were also investigated.