Synthesis, Crystal Structures And Properties Of Novel Metal Diphosphonates Coordination Polymers

In this work,we have successfully obtained eight new metal diphosphonates coordination polymers by using 4–HOOCC6H4CH2N?CH2PO3H2?2 as ligand under hydrothermal conditions.The eight title compounds were structurally characterized by X–ray single–crystal diffraction,X–ray single–crystal power diffraction,IR spectroscopy and TG analysis.Furthermore,the surface photovoltage and luminescence properties of compounds have been investigated.Interestingly,the molecular recognition property of compounds 6–8in different alkyl alcohol were also investigated by the fluorescence method.The chemical formulas are listed as follow:?1?Ni₂[{HOOCC₆H₄CH₂N?CH₂PO₃H?₂}₂?H₂O?₂]·3H₂O?2?{NH?CH₂?₂NH}_0.5[Cu{HOOCC₆H₄CH₂N?CH₂PO₃H?₂}]?3?Cu₂[{OOCC₆H₄CH₂N?CH₂PO₃??CH₂PO₃H?}?H₂O?₂]?4?Pb₂[HOOCC₆H₄CH₂N?CH₂PO₃?₂]?5?Pb[HOOCC₆H₄CH₂N?CH₂PO₃H?₂]?6?Ca[{HOOCC₆H₄CH₂N?CH₂PO₃H?₂}?H₂O?]?7?Ca[HOOCC₆H₄CH₂N?CH₂PO₃H₂??CH₂PO₃H?]₂?8?Ba[{HOOCC₆H₄CH₂N?CH₂PO₃H?₂}?H₂O?]By using the phosphonate ligand 4–HOOCC₆H₄CH₂N?CH₂PO₃H₂?₂,compounds 1–8 are obtained by hydrothermal technique.X–ray diffraction analysis exhibits that compound 1shows a 2D supramolecular layered structure through hydrogen bonding interactions.Compounds 2,4,6 and 8 feature 3D supramolecular network through hydrogen bonding interactions.Compound 3 features a 3D framework structure.Compounds 7 shows a 3D supramolecular structure by?–?stacking interactions.Thermal stabilities experiments reveal that compound 2,6–8 have the stabilized framework structures.The SPS and FISPS indicate that compounds 2 and 3 both show p–type semiconductor characteristic.Luminescence analyses show that compounds 4–8 may be good candidates for blue luminescent materials.Molecular recognition properties analyses show compound 6–8 are selective for sensing of different alkyl alcohol.