Synthesis, Structures And Properties Of Novel Metal Diphosphonates Coordination Polymers

In this paper, we have successfully obtained seven new metal diphosphonates coordination polymers by using CH3C(OH)(PO3H2)2) and4-HOOCC6H4CH2N(CH2PO3H2)2as ligands under hydrothermal conditions. All compounds were structurally characterized by X-ray single-crystal diffraction, X-ray powder diffraction, IR spectroscopy and thermogravimetric analysis. Meanwhile, the luminescent properties of compounds3and6have been studied. Molecular recognition properties of compound6have also been studied. The surface photovoltage properties of compounds1,4and5have also been investigated. The chemical formulas are listed as follow:(1)(enH2)0.5[Co0.5(hedpH2)]H2O (2)(enH2)0.5[Mn0.5(hedpH2)]H2O (3)(enH2)0.5[Cd0.5(hedpH2)]H2O (4)Fe2[{(O3PCH2)2NCH2C6H4COOH}(H2O)](5)Fe0.5[(H2O3PCH2)(HO3PCH2)NCH2C6H4COOH](6) Zn2[(O3PCH2)2NCH2C6H4COOH](7)Sr[{(H2O3PCH2)(O3PCH2)NCH2C6H4COOH}(H2O)2]By using1-hydroxyethylidenediphosphonate as the phosphonate ligand, organic-amine as template agent, compounds1-3are obtained. Compounds4-7are synthesized by direct reaction using4-HOOCC6H4CH2N(CH2PO3H2)2as the phosphonate ligand. X-ray diffraction analysis exhibits that compounds1-3are isostructural and feature2D structures through hydrogen bonding interactions. Compounds4-6show a3D supramolecular structure by π-π stacking interactions. Compound7features a2D layered structure. Thermal stabilities experiments reveal that compound6has the stabilized framework structures. The SPS and FISPS of compounds1,4and5indicate that compounds1and4show p-type semiconductor characteristic and compound5shows n-type semiconductor characteristic. Luminescence analyses show that compounds3and6will be candidate for blue luminescent materials. Molecular recognition properties analyses show compound6is selective for sensing of DMF and acetone.