Synthesis,Crystal Structures And Fluorescence Recognition Properties Of Conjugate Metal Phosphonate Coordination Polymers

In this work,by selecting(2,4,6-trimethyl-phenyl ene)bis-(m ethylene)diphosphonic acid(H4L1=C6H(CH3)3(CH2PO3H2)2)and risedronic acid(H5L2=(C5H4N)CH2C(OH)(PO3H2)(PO3H2))as ligand,four new unreported metal phosphonates have been successfully synthesized under hydrothermal conditions.The crystal structures,thermal stabilities and luminescence properties of compounds 1-4 have been investigated by X-ray single-crystal diffraction,X-ray powder diffraction,infrared spectroscopy,thermogravimetric analysis and luminescence spectroscopy.Base on the synthesis of compound 5 in our group,the identification mechanism of thymine and ions by compound 5 were discussed.Compounds 1-3 has been synthesized by using(2,4,6-trimethyl-phenylene)bis-(methylene)diphosphonic acid(H4L1=C6H(CH3)3(CH2PO3H2)2)as ligand.The compound Cd[(H2L2)(2,10-phen)](1)was synthesized by introducing a second organic ligand(1,10-phen),and compounds 2-3 are synthesized by direct assembly of organic phosphonate and metal ion.The compound 1 shows two-dimensional supramolecular structure and compound Pr[(H3L2)(H2L1)(H2O)](2)and]Nd[(H3L1)(H2L1)(H2O)](3)can be described as a 1D chain structure.By employing risedronic acid(H5L2)as ligand,compound 4 has been synthesized by direct reaction.The structure of compound Sr[(H3L2)(H2O)](4)was exhibited 1D chain,two kinds of chains are interconnected to form a 2D layer structure by ?-? stacking interactions,the two adjacent layers form a double layer structure by hydrogen bonding.The thermogravimetric curves of compounds 1-4 show that compounds 1,2 and 3 have well thermal stabilities.The compound 1 exhibit good luminescence properties by the luminescent spectrum.The luminescence recognition properties of compound 1 for the sensing of amino acid and ions were systematically investigated.The results show that compound 1 has very high quenching effects Zn2+,Co2+,CrO42-,Cr2O72-,Gln.The recognition mechanism of compound Pb3[(L3)2(O3SC6H3(COO)OH)(H2O)2](5)is discussed in detail.