Hydrothermal syntheses and crystal structures of a series of 3d–4f heterometallic tetrazole-based coordination polymers

A series of novel three-dimensional (3D) Ln(III)–Cu(I) heterometallic tetrazole-based coordination polymers, namely, [LnCu(3-tzba)2(H2O)4]n [Ln = Ho (1); Nd (2); Sm (3); Pr (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 isomorphous 3D coordination frameworks with 1D anionic chains [Ln(3-tzba)2(H2O)4]− linking the adjacent Cu(I) ions possessing an sql type net with Schläfli symbol (44). To our best knowledge, they are the first lanthanide-transition heterometal-organic coordination polymers obtained through in situ tetrazole synthesis. In addition, the thermal stability and magnetic property of 1 were also investigated.