Synthesis And Properties Of BODIPY-derived MOFs And Coordination Polymers Tuned By Different Aromatic Polycarboxylates

During the last decade, coordination polymers(CPs), especially metal–organic framework(MOF) materials have constituted an attractively versatile platform for achieving long range organization and order. Recently, many marvellous architectures have been successfully obtained. However, the design and construction of functional CPs, influenced by different factors(metal ions, organic ligands, solvent system, p H value and reaction temperature, etc), are still tremendous challenges in the fields of coordination chemistry and crystal engineering.On the other hand, due to the versatile applications in gas storage, chemical sensor, heterogeneous catalysis, molecular magnets and luminescence materials, CPs have arisen great enthusiasm of many chemists and material scientists in different areas. The constructions of functional CPs materials and the investigations of their properties are still hot spots.In this paper, we employed 2,6-dicarboxyl-BODIPY ligand(H2L) and 1,1′-(1,3-propane)bis-(2-methylbenzimidazole)(pbmb) and have successfully obtained eleven coordination polymers. What’s more, the physicochemical properties have been explored.Firstly, by using 2, 6-dicarboxyl-BODIPY ligand H2 L as chromophore linker, five coordination polymers have been formulated by changing the metal ions and auxiliary pyridine ligands. Except for two 2D-layer coordination polymers 3 and 4, the rest samples exhibit 3D metal-organic frameworks with certain pore sizes, especially MOFs 1 and 5. Spectroscopic investigations demonstrate that in case 2, the uncommon J-dimer absorption band is observed at λmax = 705 nm with a long tail into the near infrared(NIR) region at room temperature. On the other hand, in comparison with the ligand H2 L, the emission of monomer-liked BODIPY in case 3 is enhanced more than twice in the solid state.Secondly, by employing 1,1′-(1,3-propane)bis-(2-methylbenzimidazole)(pbmb) and five kinds of aromatic polycarboxylate ligands, six novel coordination polymers have been successfully obtained, which showed widely different structures and topologies determined by single-crystal X-ray diffraction analyses and further characterized by infrared spectra(IR), elemental analyses, powder X-ray diffraction(PXRD), and thermogravimetric(TG) analyses. The optical band gaps of CPs 6–11 were analyzed by diffuse-reflectance UV-vis absorption spectra. Moreover, all of the materials showed good photocatalytic activities for the degradation of methylene blue(MB) in water under high-pressure mercury lamp irradiation.