Cuprous Halide Coordination Polymers Based on Cationic [Cu4X2] and [Cu3X] Clusters and [Cu2Br]n Layers with Tetrazolates as Assembling Ligands: Highly Connected Networks and Halide‐Dependent Luminescence

Abstract

AbstractFive tetrazolate‐based coordination polymers with cationic copper(I) halide motifs, namely, Cu4(tta)2Cl2 (1, tta = tetrazolate), Cu4(tta)2Br2 (2), Cu2(tta)I (3), Cu3(mtta)2Cl (4, mtta = 5‐methyltetrazolate), and Cu2(tta)Br (5) were prepared by hydro(solvo)thermal reactions of CuX2 or CuX with tetrazolato ligands in the presence of HX. Compounds 1, 2, and 3 show eight‐connected square‐planar layered structures constructed with butterfly‐like [Cu4X2]2+ (X = Cl, Br, I) clusters and μ4‐tta groups. Isomorphs 1 and 2 crystallize in the orthorhombic space group Pbca, but 3 crystallizes in the orthorhombic space group Pbam, because each μ4‐tta group is coordinated to three butterfly‐like clusters rather than four in 1 and 2. To the best of our knowledge, 1, 2, and 3 represent the only 2D coordination polymers with eight‐connected square planar topology to date. Compound 4 is a [Cu3Cl]2+ cluster based on the undocumented ten‐connected ZrIn2 topological framework. Compound 5 has a 3D pillar layered framework constructed with [Cu2Br]nn+ cationic layers. Compounds 1, 2, 4, and 5 exhibit strong green‐blue emission in the solid state at room temperature, whereas cuprous iodide complex 3 shows strong red luminescence.