Synthesis,Crystal Structures And Properties Of Chiral And Achiral Metal Phosphonates Functional Materials

Metal phosphonate functional materials as a new class of inorganic-organic hybrid materials,due to their broad application prospects in the fields of adsorption,magnetism,molecular recognition,ion identification,etc,have attracted wide attention of chemical workers in recent years.In this work,the hydrothermal synthesis method was used to synthesize four kinds of chiral and achiral that were not reported in the literature by using ethyl p-carboxybenzylphosphonate(H2L=4-HOOCC6H4CH2PO(OH)(OC2H5))as ligand.Using ethyl p-carboxybenzylphosphonate(H2L)as an organic phosphonate ligand,a compound Co[(L)(2,2'-bipy)(H2O)](1)with a chiral structure was synthesized by introducing a second ligand(2,2'-bipy,4,4'-bipy)and the non-chiral compound Cd[(HOOCC6H4CH2PO3H)2(4,4'-bipy)(H2O)2](2)synthesized by direct synthesis two different structures of the compound Ca(HL)2(3)and Sr[(HOOCC6H4CH2PO3H)2(H2O)3](4).The crystal structure and thermal stability of the synthesized compounds were studied by X-ray single crystal diffraction,X-ray powder diffraction,TG analysis and IR spectroscopy.The optical activities of chiral compounds 1 have been studied by means of circular dichroism(CD)spectra.Using fluorescence spectroscopy,the luminescence properties of compounds 2,3 and 4 were studied.In addition,the properties of compounds 2 and 3 for selectively recognizing biological amino acids were also studied by means of fluorescence measurements.At the same time,the recognition performance of the anions and cations of compounds 2 and 3 was also studied.X-ray single crystal diffraction results show that compound 1 is a chiral compound and exhibits a two-dimensional layered structure,and a three-dimensional supramolecular structure is further formed by ?-? stacking.Compounds 2 and 4 are one-dimensional chains of three-dimensional supramolecular structures constructed by hydrogen bonds.Compound 3 exhibits a three-dimensional framework structure.By analyzing the thermogravimetric curves of Compounds 1-4,the results show that Compound 3 has relatively good thermal stability.It can be found through fluorescence test that compounds 2,3,and 4 all have good fluorescence emission properties.In addition,the use of fluorescence analysis means to selectively identify compounds 2 and 3 bio-small molecule amino acid properties,the results show that compound 2 has a clear recognition of tryptophan molecules,and compound 3 on arginine and histidine All have better fluorescence quenching response.At the same time,the recognition properties of the anions and cations of compounds 2 and 3 were also studied in depth.Compound 2 showed good fluorescence recognition response to CrO42-,Cr2O72-,Ru³⁺,Fe³⁺,and compound 3 to MnO4-,CrO42-,Cr2O72-and Ce³⁺have obvious recognition effects.