Syntheses, Structures, and Photoluminescence of a Series of Three-Dimensional Cd(II) Frameworks with a Flexible Ligand, 1,5-Bis(5-tetrazolo)-3-oxapentane

Six novel Cd-11-based metal-organic frameworks with a flexible ligand 1,5-bis(5-tetrazolo)-3-oxapentane) (H(2)btz), [Cd-5(N-3)(6)(btz)(2)](n) (1). [Cd5X2(N-3)(4)(btz)(2)](n) (X = Cl (2), Br (3)). [Cd-3(N-3)(2)(btz)(2)](n) (4), and [Cd3X2(btz)(2)](n) (X = Cl (5), Br (6)). have been successfully synthesized under hydrothermal reactions and structurally characterized by single-crystal X-ray diffraction. The H(2)btz ligands in the complexes 1-4 can be in situ generated from the [2 + 3]-cycloaddition reaction of the precursor bis(2-cyanoethyl)ether (BCEE) and NaN3 under Cd-11-catalyzed. Single-crystal X-ray diffraction analysis revealed that all of the complexes 1-6 displayed rich three-dimensional (3D) frameworks constructed from Cd2+, btz(2-) ligand and bridging anions. It has been found that the ingenious changes of anions finally lead to the structural diversity in 1-6. such as N-3(-) for 1 and 4, N-3(-) and Cl- for 2, N-3(-) and Br- for 3, Cl- for 5, and Br- for 6. Additionally, the X-ray powder diffraction (XRPD), thermal stability, and the photoluminescence properties at room temperature in the solid state for 1-6 have also been studied.