Syntheses, structures and photoluminescent properties of Zn(Ⅱ)/Co(Ⅱ) coordination polymers based on flexible tetracarboxylate ligand of 5,5′-(butane-1,4-diyl)-bis(oxy)-di isophthalic acid

Three new mixed-ligand metal-organic frameworks based on 5,5′-(butane-1,4- diyl)-bis(oxy)-diisophthalic acid and transitional metal cations with the help of two ancillary bridging N-donor pyridyl and imidazole linkers, [Zn(L)0.5(4,4′-bpy)]·2(H2O) (1), [M(L)0.5(bib)]·4(H2O) (M = Zn (2), Co (3)), (4,4′-bpy=4,4′–bipyridine, bib=1,4-bis (1H-imidazol-1-yl)-butane), have been synthesized under solvothermal conditions. Their structures and properties were determined by single-crystal and powder X-ray diffraction analyses, IR spectra, elemental analyses and thermogravimetric analyses (TGA). Compounds 1–3 display a 3D 3-fold interpenetrated frameworks linked by the L4− ligands, ancillary N-donor linkers and the free water molecules in the crystal lattice. Topological analysis reveals that 1–3 are a (4,4)-connected bbf topology net with the (64·82)(66) topology. The effects of the L4− anions, the N-donor ligands, and the metal ions on the structures of the coordination polymers have been discussed. Furthermore, luminescence properties and thermogravimetric properties of these compounds were investigated.

Graphical abstractThree new compounds of MOFs have been prepared and characterized. The luminescence properties and thermogravimetric properties of compounds were investigated.Figure optionsDownload full-size imageDownload as PowerPoint slide