Synthesis, Crystal Structures And Properties Of Carboxyphosphonates Functional Materials

In this article, seven new phosphonate coordination polymers have been synthesized by using2-hydroxyphosphonoacetic acid (H2O3PCH(OH)CO2H) and4-carboxyphenylphosphonic acid (4-cppH3) as ligands. The title compounds were structurally characterized by X-ray single-crystal diffraction, X-ray powder diffraction, infrared spectroscopy and thermogravimetric analysis. Furthermore, the luminescence properties and surface photovoltage properties of compounds have been studied. Interestingly, the molecular recognition property of compounds2-5in different alkyl alcohol and carbonyl derivatives emulsions were also investigated by the fluorescence properties. The chemical formulas are listed as follow:(1)[Co2(HO3PCH(OH)CO2)(H2O3PCH(OH)CO2)2]·2NH(CH3)2·3H2O (2) Cd3[(4-cppH)2(4-cppH2)2](3) Cd[(4-cppH)(2,2’-bipy)](4)[Cd3(4-cpp)2(1,10-phen)3]·6H2O (5)[Cd(4-cppH)(4,4’-bipy)(H2O)2]·2H2O (6)[Zn3(4-cpp)2(1,10-phen)3]·7H2O (7) Zn2[(4-cpp)(2,2’-bipy)(OH)]Compound1is obtained by mixed-solvothermal technique, using2-hydroxyphosphonoacetic acid (H2O3PCH(OH)CO2H) as the phosphonate ligand. X-ray diffraction analysis shows that compound1features2D layered structure. Compounds2-7are obtained by4-carboxyphenylphosphonic acid (4-cppHb) as the phosphonate ligand under hydrothermal conditions. X-ray diffraction analysis shows that compound2forms layer structure, and neighboring layers compose into a3D supramolecular network by hydrogen bonding interactions. Compounds3-7all show a layered structure, which are synthesized by using4-carboxyphenylphosphonic acid (4-cppH3) as ligand and2,2’-bipy,1,10-phen or4,4’-bipy as the second metal linker. Compounds4,6and7are further assembled into a3D supramolecular structure through π-π stacking interactions. Compound5also can be described as a3D supramolecular structure, which is prepared by hydrogen bonding interactions. Thermal stabilities experiments of compounds1-7reveal that compounds2and 7have the stabilized framework structures from room temperature to330℃. The SPS and FISPS of compound1indicate that it exhibits surface photovoltage properties and show p-type semiconductor characteristic. The luminescence analyses indicate that compounds2-7are candidates for blue-light luminescent materials. The molecular recognition property of compound2-5showed that compounds3-5did not exhibit the potential for the sensing of guest molecules and compound1may be potentially used for the sensing of DMF and acetone.