Synthesis,Crystal Structures And Properties Of Functionalized Metal Phosphonate Materials

In this work,three novel metal phosphonate functional materials have been successfully synthesizedunderhydrothermalconditionsbyemploying H₂O₃PCH₂NH(C₂H₄)₂NHCH₂PO₃H₂(H₄L₁)and 4–HOOCC₆H₄CH₂CH₂PO(OH)(OC₂H₅)(H₂L₂)as phosphonic acid ligands.All three compounds were structurally characterized by X-ray single–crystal diffraction,X–ray powder diffraction,infrared(IR)spectroscopy and thermogravimetric(TG)analysis.The luminescence properties of compounds 1 and 3 have been studied.Meanwhile,compounds 1 and 3 have been realized for sensing of ions and amino acids by the luminescent method.Moreover,we have done a deep research on the synthesized compounds 4–8 in this paper.Based on the previous work,the synthesis conditions and crystal growing rules of this series of compounds have been further explored and the powders with high purity were obtained.In addition,the recognition properties of compound 4 and the magnetic property of compound 7 were investigated,so that the work has been further improved.The chemical constitution formulas of compounds 1–8 are listed as follow:[Pb₂(H₂L₁)_0.5(bts)(H₂O)₂]·H₂O(1)Fe[(HOOCC₆H₄CH₂PO₂(OC₂H₅)]₂(2)Pb[OOCC₆H₄CH₂PO₂(OC₂H₅)]·H₂O(3)[Ln₂(H₃L₃)(C₂O₄)₃(H₂O)₄]·2H₂O[Ln=Eu(4),Gd(5),Tb(6),Dy(7),Er(8)]Compound 1 has been synthesized by using H₂O₃PCH₂NH(C₂H₄)₂NHCH₂PO₃H₂(H₄L₁)as phosphonic acid ligand and Na H₂bts as the second metal linker.Compounds 2 and 3 have been obtained with 4–HOOCC₆H₄CH₂PO(OH)(OC₂H₅)(H₂L₂)as phosphonate acid ligand.And they all feature 3D framework structures.Thermal stabilies experiments reveal that the framework of compounds 1–3 are stable.The luminescence properties of compounds 1 and 3indicate that they are good luminescent materials.Compounds 1 and 3 have been realized for ions and amino acid recognition properties.Interestingly,they all exhibit highly selective sensing of Fe³⁺and Cr₂O₇^2-ions.Moreover,compound 1 has a selective recognition effect on crysteine,while compound 3 has a recognition effect on lysine.Meanwhile,the study of compound 4 as a potential luminescence sensor was done.The results reveal that compound 4not only shows a selective response to Cr₂O₇^2-anion and arginine,but displays great chemical resistance to both acidic and alkaline solutions with a p H ranging from 3 to 13.In addition,antiferromagnetic interactions also exist between Dy^? ions.