Synthesis,crystal Structures And Properties Of Functionalized Metal Phosphonate Coordination Polymers

In this work,by selecting N,N'–bis(phosphonomethyl)aminoacetic acid(H₅L₁=HOOCCH₂N(CH₂PO₃H₂)₂),p–nitrobenzyl phosphonic acid(H₂L₂=O₂NC₆H₄CH₂PO₃H₂),3–ammonium–1–hydroxypropylidene–1,1–bisphosphonate(H₅L₃=H₂N(CH₂)₂C(OH)(PO₃H₂)₂)and 4–aminomethyl benzoic acid diphosphonic acid(H₅L₄=HOOCC₆H₄CH₂N(CH₂PO₃H₂)₂)as organic phosphonic acid ligands,seven new unreported metal phosphonates have been successfully synthesized through hydrothermal conditions.There are two methods that have been employed to obtain such materials.One is the direct assembly of phosphonic acid ligand with metal ions in the synthesis of metal phosphonate materials;the other is by introducing a second organic ligand(4,4'–bipy)into the structure of metal phosphonate materials.The crystal structure and thermal stability of the synthesized compounds were studied by X–ray single crystal diffraction,X–ray powder diffraction,IR spectroscopy and thermogravimetric analysis(TG).The physical adsorption property of compound 1 was studied by gas adsorption apparatus,the dye adsorption of compound 1 was studied by ultraviolet spectrophotometry,the catalytic performance of compound 2 was studied by meteorological chromatography.The chemical formulas are listed as follow:(1)Ni₂[(HL₁)(4,4'–bipy)(H₂O)]·4H₂O(2)Cu_2.5[(L₂)(CH₃COO)(H₂O)₂](3)Zn[(L₂)(H₂O)](4)Cd[(L₂)(H₂O)₂]·H₂O(5)Fe_0.5[H₄L₃](6)Co[(H₄L₃)₂](7)Cd[(HL'₄)(H₂O)]X-ray diffraction analysis exhibit that compound 1 features a three–dimensional skeleton structure connected by 4,4'–bipy;compounds 2 and 4 show 2D layered structures;compounds 3 and 5 feature three–dimensional supramolecular structure which were constructed by Hydrogen bonds;Compound 6 features double layers supramolecular structure through hydrogen bonding;Compound 7 can be described as a 3D supramolecular structure,which is assembled by hydrogen bonding.TG curves and XRD of compounds 1–7 revealed that compounds 5 and 6 had good thermal stability and could be stabilized above 300°C.Physical adsorption studies showed that compound 1 had unique pore characteristics and good N₂adsorption capacity.UV spectrophotometry showed that compound 1 had selective adsorption effect on Coomassie Brilliant Blue(CBB).Compound 2 had good property in catalyzing the ketalization reaction of cyclohexanone and ethylene glycol.