A New Three-dimensional Cd Metal-organic Framework Based on a C-centered Tripodal Flexible Carboxylate and 1,2-Bis(4-pyridyl)ethane Mixed Ligands

A new MOF {[Cd3(TCOPM)2bpe]-7(H2O)-2DMF}n based on a C-centered tripodal flexible carboxylate ligand and l,2-bis(4-pyridyl)ethane ligand(H3TCOPM = tris(p-carboxyphenyl)methane,bpe = l,2-bis(4-pyridyl) ethane) has been synthesized by the hydrothermal reaction in mixed DMF/H2 O solution under 95 °C.The structure has been determined by single-crystal X-ray diffraction analysis and elemental analysis,IR spectroscopy,and thermogravimetric analysis.Crystal data for the title complex are as follows:triclinic system,space group P1 with α =9.2637(14),b = 13.273(2),c = 14.160(2) A,α = 9.2637(14),β = 13.273(2),y = 105.585(2)°,V =1487.6(4) A3,Mr= 1268.11,Z = 1,F(000) = 628,Dc = 1.416 g/cm3,μ(MoKα) = 1.110 mm-1,R =0.0482 and wR = 0.1444 for 5207 observed reflections with I>2σ(Ⅰ).MOF 1 consists of an infinite3 D network using TCOPM3- and bpe as mixed bridge ligands.Fluorescence spectrum measurement indicates that MOF 1 shows strong fluorescence emission at 437 nm(λmax) in the solid state at room temperature and realizes tunable emission spectrum through tuning from single to mixed ligand.