Synthesis,Crystal Structures,Luminescent And Surface Photovoltage Properties Of Novel Metal Phosphonate Functional Materials

In this work,nine new phosphonate coordination polymers with phenylphosphonic acid(H2L = C6H5PO3H2),N-morpholinomethylphosphonic acid(H2O3PCH2N(CH2CH2)2O),1-hydroxyethylidenediphosphonic acid(hedpH4 = CH3C(OH)(PO3H2)2)and 1-hydro xy--2-(3-pyridyl)ethylidene-1,1-diphosphonic acid(H4L’ =(C5H4N)CH2C(OH)(PO3H2)2)as the phosphonate ligands,2,2’-bpyridine(2,2’-bipy),1,10-phenanthroline(1,10-phen),1,4-benzenedicarboxylic acid(H2bdc)and oxalate as the second metal linker have been successfully synthesized under hydrothermal and mixed-solvothermal conditions,respectively.All compounds were structurally characterized by X-ray single-crystal diffraction,X-ray powder diffraction,infrared spectroscopy and thermogravimetric analysis.Meanwhile,The surface photovoltage properties of compounds 1,2,4,8,9 and the luminescence properties of compounds 3,5,6,8 have been studied.The chemical formulas are listed as follow:(1)[Cu(2,2’-bipy)(HL)2](2)[Cu2(1,10-phen)2(HL)2(L)]H2L(3)[Zn(1,10-phen)(HL)2](4)[Mn(1,10-phen)(HL)2(H2L)](5)[Cd(1,10-phen)(HL)2(H2L)](6)[Zn{O(CH2CH2)2NCH2PO3}(H2bdc)0.5](7)[Ho2{O(CH2CH2)2NHCH2PO3H}(C2O4)3(H2O)3]·H2O(8)[Zn(1,10-Phen)VO(OH){CH3C(OH)(PO3)2}]·H2O(9)[Fe1.5(HL’)(H2O)]·NH(CH3)2·H2OCompounds 1-5 are synthesized by phenylphosphonic acid(H2L = C6H5PO3H2)as the phosphonate ligand,2,2’-bipyridine(2,2-bipy)and 1,10-phenanthroline(1,10-phen)as the second ligands under hydrothermal conditions.X-ray diffraction analysis shows that compound 1 forms a 1D supramolecular structure through π-π stacking interactions.Compounds 2 and 3 all show a 3D supramolecular structure.Compound 2 exhibits π-πstacking and hydrogen bonding interactions and compound 3 shows a 3D supramolecular network through three types of π-π stacking interactions.Compounds 4 and 5 are isomorphic through π-π stacking and hydrogen bonding interactions to form a 2D supramolecular strcture.Compounds 6 and 7 are synthesized by N-morpholinomethylphosphonic acid(H2O3PCH2N(CH2CH2)2O)as the phosphonate ligand,1,4-benzenedicarboxylic acid(H2bdc)and oxalate as the second metal linker.Compound 6 features 2D layered structure and compound 7 exhibits a 3D framework structure.Compound 8 is obtained by using 1-hydroxyethylidenediphosphonic acid(hedpH4 = CH3C(OH)(PO3H2)2)as the phosphonate ligand.X-ray diffraction analysis shows that compound 8 features 2D layered structure,and the neighboring layers are further assembled into a 3D supramolecular structure through π-πstacking interactions.Compound 9 is obtained by using 1-hydroxy-2-(3-pyridyl)ethylidene-1,1-dipho sphonic acid(H4L’ =(C5H4N)CH2C(OH)(PO3H2)2)as the phosphonate ligand under mixed-solvothermal conditions.X-ray diffraction analysis shows that compound 9 features three-dimensional framework structure.Therml stabilities experiments of compounds 1-9 reveal that compounds 2 and 3 have the stabilized framework structures from room temperature to 260℃.The SPS and FISPS of compounds 1,2,4,8,9 indicate that they exhibit surface photo voltage properties and show p-type semiconductor characteristic.The luminescence analyses indicate that compounds 3,5,6,8 are candidates for blue-light luminescent materials.