A novel metal–organic framework with bifunctional tetrazolate-5-carboxylate ligand: Crystal structure and luminescent properties

Hydrothermal reaction of NaN3, Na(4-cba) (4-Hcba = 4-cyanobenzoic acid) and ZnBr2 afforded a novel 3D Zn(II) coordination polymer [Zn2(4-tzba)2(H2O)]n 1 (4-H2tzba = 4-(5H-tetrazol)benzoic acid). In situ [2 + 3] cycloaddition reaction of nitrile and azide in the presence of ZnBr2 yielded tetrazolate-5-carboxylate 4-tzba2− ligand. Compound 1 displays an unprecedented four-connected topological network with 1D hexagonal channels constructed from trigonal rings [Zn3(4-tzba)6]. The solid-state photoluminescent studies revealed that 1 exhibits a strong blue emission mainly originating from 4-tzba2− ligand-centered charge transition.