Three novel zinc(II) metal-organic frameworks based on three tetrazolate ligands: synthesis, structures and photoluminescence

Three metal-organic frameworks (MOFs), namely [Zn(BPT)H2O] (JUC-121), [Zn-5(IBT)(6)]center dot 8[H2N(CH3)(2)]center dot DMA (JUC-122) and [Zn(TPD)(H2O)(2)]center dot 0.5H(2)O (JUC-123) (JUC = Jilin University, China), H2BPT = (5-bromo-1,3-phenylene) bis(tetrazole), H3IBT = 4,5-bis(tetrazol-5-yl)imidazole and H2TPD = 3,5-di(tetrazol-5-yl) pyridine, were obtained by the reactions of Zn(NO3)(2 center dot)6H(2)O and three tetrazolate ligands, which were characterized by single crystal X-ray diffraction, thermal gravimetric analyses (TGA), Fourier-transform infrared spectra (FT-IR), elemental analysis (CHN) and powder X-ray diffraction (PXRD). From the crystal structures of these complexes and the coordination modes of the ligands, we can see that the tetrazolate ligands have multi-connectivity abilities to obtain intriguing varieties of molecular architectures. JUC-121 displays a three-dimensional (3D) network with the point symbol (4 center dot 6(5))(2)(4(2)center dot 8(4))(6(4)center dot 8(2)). JUC-122 shows a two-dimensional (2D) framework with the point symbol (24(3))(2)(24)(9) and JUC-123 has a 2D bimodal (3, 3)-connected net with the point symbol (4 center dot 8(2)). The solid-state fluorescent spectra of JUC-121, JUC-122, JUC-123 and the free ligands were measured at room temperature.