Syntheses,Structures And Properties Of Peroxy-containing Phosphotungstates And Its Derivatives

The reaction of sodium tungstate,and phosphoric acid in a hydrogen peroxide solution led to the isolation of three series of novel peroxophosphotungstate and its derivatives after adding rare earth solution,which have been thoroughly characterized by X-ray single-crystal analysis,X-ray powder diffraction,IR,UV-vis spectroscopy,thermogravimetric analyses,elemental analyses,field emmission scaning photoelectron spectroscopy,fluorescent properties,magnetic and 31P NMR studies.1.Two peroxophosphotungstate compounds based on[(PO4)P2W6(O2)6(OH)2O18]7-were synthesized for the first time.Cs5.5Na1.5[(PO4)P2W6(O2)6(OH)2O18]1·6H2O(1),C15H86N45[(PO4)2P4W12(O2)12(OH)4O36]·12H2O(2).The structure of 1 and 2 are isomorphic compounds,X-ray single-crystal analysis indicates that the polyanion consists of a {PO4}block supporting two {P2W3(O2)3(OH)O13} groups.Different from the well-known Venturello cluster {PO4[W(O)(O2)2]4}3-,the two {P2W3(O2)3(OH)O13} groups in 1 are additionally connected together by a phosphorus atom.However,four {W(O)(O2)2} groups in Venturello cluster are additionally connected together by a phosphorus atom.In addition,the solution behavior of compound 1 was studied by UV-vis and 31P NMR.2.Three two-dimensional rare earth derivatives based on peroxyphosphotungstic anions were synthesized for the first time.Cs3H5[Ln2(H2O)5P2W6(O2)4O26]·nH2O(Ln = Pr(3,n = 23),Nd(4,n = 23))and Sm(5,n = 21)),3-5 are also isostructural compounds and formed by one[P2W6(O2)4O26]14-moieties that anchor a[Ln2(H2O)5]3+(Ln = Pr,Nd,Sm)core through the W-O-Lnl bonds,then through the P-O-Ln2 bonds.The Solid fluorescence analysis of compunds 3 and 5 show that the characteristic emission spectra of Pr3+ and Sm3+respectively.3.Six one-dimensional chain rare earth derivatives based on peroxyphosphotungstic anions were synthesized for the first time.Cs5H6[Ln(H2O)4P4W6(O2)6(OH)2O28]·nH2O(Ln = Gd(6,n = 18),Tb(7,n = 18),Dy(8,n ?18),Ho(9,n = 20),Er(10,n = 18),and Yb(11,n = 15)).6-11 are also isostructural compounds and formed by two[P2W3(O2)3(OH)O14]7-moieties that anchor a[Ln(H2O)4]3+(Ln=Gd,Tb,Dy,Ho,Er,Yb)core through the Ln-O-P bonds.The Solid fluorescence analysis of compunds 7,8,9,and 10 show that the characteristic emission spectra of Tb3+,Dy3+,Ho3+,and Er3+ respectively,the fluorescence life of compound 7 is as long as 510.77?s.