Two novel 3D MOFs based on the biphenyl-2,4,6,3 ',5 '-pentacarboxylic acid ligand: Synthesis, crystal structure and luminescence properties

摘要

Two novel 3D metal-organic frameworks [Cd-3 (bpbc)(mu(3)-OH)(H2O)(3)]center dot H2O (1) and [Zn2Na (bpbc)(DMF)(1.5)(EtOH)(0.5 )(H2O)(5)]center dot 0.5H(2)O (2) have been synthesized by using biphenyl-2, 4, 6, 3', 5'-pentacarboxylic acid (H(5)bpbc) as the ligand under solvothermal/hydrothermal conditions. The complexes were characterized by elemental analysis, single-crystal X-ray diffraction (XRD), powder X-ray diffraction (PXRD), IR spectra and thermogravimetric analysis (TGA). Structural analysis revealed that complex 1 shows a (5, 10)-connected 3D network based on the [Cd-6 (COO)(10)(mu(3)-OH)(2)] SBUs with unusual topology, while complex 2 exhibits a (3, 3, 6)-connected 3D framework. The structural difference between 1 and 2 indicated that the coordination fashion of bpbc(5-) and the kind of metal ions could play critical role in the construction of MOFs. In addition, new fluorescence emissions were observed for 1 and 2, and the solid state luminescent properties were investigated.