Synthesis,Crystal Structures And P Roperties Of New Metal Phosphonates Functional Materials

In this work,by employing 2,4,6-trimethyl-1,3-phenylene)bis(methylene)diphosphonic acid(H4L1)and 4-HOOC-C6H4-CH2N(CH2PO3H2)2(H5L2)as phosphonate ligands,we have successfully synthesized six new metal phosphonates under hydrothermal conditions.All six compounds were structurally characterized by X-ray single-crystal diffraction,X-ray powder diffraction,IR spectroscopy and thermogravimetric analysis.Furthermore,the luminescence properties of compounds 1,4,5,6 have been studied.Interesingly,compound 6 has been realized for sensing of nitro explosives by the fluorescence method.The chemical constitution formulas of compounds 1-6 are listed as follow:(1)Pb4(L1)2(2)La[H3L1)(H2LI)(H2O)](3)Ce[(H3L1)(H2L1)(H2O)](4)[Mn(H2L1)(4,4’-bipy)(H2O)]-4H2O(5)[Co(H2L1)(4,4’-bipy)1.5(H2O)2]·1.5(4,4’-bipy)·7H2O(6)Zn(H4L2)2Compounds 1-3 have been synthesized by using(2,4,6-trimethyl-1,3-phenylene)bis(methylene)diphosphonic acid(H4L1)as the phosphonate ligand.By using 4,4’-bipy as the second ligand,compounds 4 and 5 have also been obtained with H4L1.Compound 1 shows a 2D layer structure.Compounds 2 and 3 are isostructural,which adopt 1D infinite chain structure.Compounds 4 and 5 feature 3D framework and 1D double chain structure,respectively.By introducing 4-HOOC-C6H4-CH2N(CH2PO3H2)2(H5L2)as the phosphonate ligand,we sucessfully obtain compound 6.There exist π-πstacking interations between adjacent inorganic layers in compound 6,thus forming a 3D supramolecular structure.The results of thermal analysis show that the framework structures of compounds 1 and 6 are stable.The luminescence properties of compounds 1,4,5,6 indicate that they are good luminescent materials.Furthermore,compound 6 has been realized for sensitive sensing of nitro explosives by the luminescent method.