Hydrothermal syntheses, crystal structures and luminescence properties of zinc(II) and cadmium(II) coordination polymers based on bifunctional 3,2′:6′,3′′-terpyridine-4′-carboxylic acid

Five new coordination polymers, [Zn2(ctpy)2Cl2]n (1), [Zn2(ctpy)2(ox)(H2O)2]n (2), [Zn2(ctpy)(3-btc)(H2O)]n·0.5nH2O (3), [Cd(ctpy)2(H2O)]n (4), [Cd4(ctpy)2(2-btc)2(H2O)2]n·2nH2O (5), (Hctpy=3,2′:6′,3′′-terpyridine-4′-carboxylic acid, H2ox=oxalic acid, H3(3-btc)=1,3,5-benzenetricarboxylic acid, H3(2-btc)=1,2,4-benzenetricarboxylic acid) have been synthesized under hydrothermal conditions and characterized by elemental analysis, IR spectroscopy, and single-crystal X-ray diffraction. Compounds 1–2 are a one-dimensional chain with weak interactions to form 3D supramolecular structures. Compound 3 is a 4-nodal 3D topology framework comprised of binuclear zinc units and (ctpy)− anions. Compound 4 shows two dimensional net. Compound 5 is a (4,5,6)-connected framework with {44·62}{46·64}2{49·66} topology. In addition, the thermal stabilities and photoluminescence properties of 1–5 were also studied in the solid state.

Five new Zn/Cd compounds with 3,2′:6′,3′′-terpyridine-4′-carboxylic acid were prepared. The photoluminescence and thermal stabilities properties of 1–5 were investigated in the solid state.Figure optionsDownload as PowerPoint slideHighlights
► Five new zinc/cadmium metal–organic frameworks have been hydrothermal synthesized.
► The structural variation is attributed to the diverse metal ions and auxiliary ligand.
► Compounds 1–5 exhibit 1D ring chain, 2D layer and 3D open-framework, respectively.
► These compounds exhibit strong solid state luminescence emission at room temperature.