The present paper covers seven rare earth-containing tungstosilicate heteropoly complexes LnHSiW_(12)O_(40)·xH_2O with Keggin structure(Ln=La,Ce,Pr,Nd,Sm,Eu and Gd)snythesized by double decomposition reaction.The...The present paper covers seven rare earth-containing tungstosilicate heteropoly complexes LnHSiW_(12)O_(40)·xH_2O with Keggin structure(Ln=La,Ce,Pr,Nd,Sm,Eu and Gd)snythesized by double decomposition reaction.The synthesized heteropoly complexes were characterized by ICP,^(29)Si-NMR,XPS, XRD,IR,UV,polarogram,CV and TG-DTA.The relationship between the structure of the synthesized heteropoly complexes and their properties is discussed.展开更多
The capability of the synthesized heteropoly complexes of rare earths {K10 [(O39W11Si) Ln(Gly)3Ln(SiW11O39)]?H2O (Ln=La, Pr, Nd, Sm, Eu, Gd, Tb, Dy)} as the catalyst promoter in the synthesis of the ethyl acetate was ...The capability of the synthesized heteropoly complexes of rare earths {K10 [(O39W11Si) Ln(Gly)3Ln(SiW11O39)]?H2O (Ln=La, Pr, Nd, Sm, Eu, Gd, Tb, Dy)} as the catalyst promoter in the synthesis of the ethyl acetate was studied. The results showed that the quantity of H2SO4 used for synthesizing the ethyl acetate can be reduced by 75% and the yield reached 98% at the optional condition.展开更多
New indium heteropoly undecatungstometalate complexes of general formula K_n In( H_2O) MW_(11)O_(39) .xH_2O (M = Cr(Ⅲ) , Fe( Ⅲ ), Co(Ⅱ) or Zn( Ⅱ) ) were prepared by the stepwise acidification and the stepwise addi...New indium heteropoly undecatungstometalate complexes of general formula K_n In( H_2O) MW_(11)O_(39) .xH_2O (M = Cr(Ⅲ) , Fe( Ⅲ ), Co(Ⅱ) or Zn( Ⅱ) ) were prepared by the stepwise acidification and the stepwise addition of materials. The products were characterized by elemental analysis, ion-exchange, IRspectra, UV spectra, X-ray powder diffraction and thermal analysis. The results show that the structure ofthe products derives from the Keggin structure. Their themial stability is higher than that of the homolo-gous dedecatungstometalates .展开更多
Lanthanide heteropoly compounds K15[Ln(HSiW9O34)2]·28H2O(Ln = La, Ce, Nd), denoted as Ln(SiW9)2, were synthesized and characterized by element analysis, TG-DTA, IR, UV, XPS and XRD. The results show that partial ...Lanthanide heteropoly compounds K15[Ln(HSiW9O34)2]·28H2O(Ln = La, Ce, Nd), denoted as Ln(SiW9)2, were synthesized and characterized by element analysis, TG-DTA, IR, UV, XPS and XRD. The results show that partial oxygen in Ln(SiW9)2 was coordinated with Ln3- , where Ln-3 was in the inner side of the heteropoly anions, while the fundamental structure of SiW9 had little change. The result was supported by ion exchange experiment.展开更多
The title complexes KaHb[M(SiW9O34)2]?mH2O(M=Ni,Cu,Zn,Fe or Mn) were synthesized by SiW9O34 10? with transition metal respectively and their structure were characterized by mean of elemental analysis, TG-DTA, IR spect...The title complexes KaHb[M(SiW9O34)2]?mH2O(M=Ni,Cu,Zn,Fe or Mn) were synthesized by SiW9O34 10? with transition metal respectively and their structure were characterized by mean of elemental analysis, TG-DTA, IR spectra and, UV spectra. In addition, their redox properties in solution were investigated using polarographic and cyclic voltammographic methods. Experimental results indicated that the complexes have Keggin structure and that the heteropolyanions underwent two-step, two-electron tungsten reduction processes.展开更多
Seven new-type pentabasic heteropoly complexes with the general molecular formula K 10H 5[Ln(PMo 5W 4V 2O 39) 2]·nH 2O(Ln=La, Ce, Pr, Nd, Eu, Gd, Dy) were synthesized. The results of IR, UV, 31P...Seven new-type pentabasic heteropoly complexes with the general molecular formula K 10H 5[Ln(PMo 5W 4V 2O 39) 2]·nH 2O(Ln=La, Ce, Pr, Nd, Eu, Gd, Dy) were synthesized. The results of IR, UV, 31P, 51V NMR and X-ray powder diffraction pattern demonstrate that the product still maintains Keggin structure. The thermal stability studied by water solubility test, TG-DTA, XRD and IR at various temperature shows that the range of pyrolysis temperature is from 500～550 ℃. The catalytic action varies according to the contents of rare earths which are used to catalyze the decomposition of hydrogen peroxide.展开更多
Eight new compounds of α- and β- M2H4[SiW16Cr2(OH2)2O ] .xH2O types, where M = K, Me4N, Et4N or n-Bu4N, and 0+6=6,were synthesized from trivacant heteropoly tungstate α-and β-[SiW9O34]10 precursors, and characteri...Eight new compounds of α- and β- M2H4[SiW16Cr2(OH2)2O ] .xH2O types, where M = K, Me4N, Et4N or n-Bu4N, and 0+6=6,were synthesized from trivacant heteropoly tungstate α-and β-[SiW9O34]10 precursors, and characterized by elemental analysis, thermal gravimetric analysis, IR, UV-visible spectra, X-ray photoelectron spectroscopy(XPS), polarography, magnetic measurements and X-ray powder diffraction. The IR and UV spectra conJEirm that α-and β-[SlW10Cr2(OH2)2O24]6- isomers possess α-and β-Keg-gin structures. The differences between α-and β-isomers in IR, UV spectra and polarography are discussed.展开更多
Heteropoly-complexes K17[Ln(CuW11O39)2].xH2O(Ln = La, Ce, Pr, Nd, Sm, Eu, Gd, Dy) were prepared. The properties of the products were investigated by ion-exchange, conductometric titration, IR, UV and X-ray powder diff...Heteropoly-complexes K17[Ln(CuW11O39)2].xH2O(Ln = La, Ce, Pr, Nd, Sm, Eu, Gd, Dy) were prepared. The properties of the products were investigated by ion-exchange, conductometric titration, IR, UV and X-ray powder diffraction. The results show that the structure of the products is similar to that of U(a-Ge11O39)2 and consistent with the model proposed by Peacock.展开更多
Two new compounds of A- type α-and β-K4.5H2.5[SiW9Cr3(OH2)3O37]·xH2O were synthesized. The two kinds of isomers of α-and β-SiW12-xCrx(x=2, 3) were identified by Second-derivative IR spectroscopy and cyclic vo...Two new compounds of A- type α-and β-K4.5H2.5[SiW9Cr3(OH2)3O37]·xH2O were synthesized. The two kinds of isomers of α-and β-SiW12-xCrx(x=2, 3) were identified by Second-derivative IR spectroscopy and cyclic voltammetry. The numbers of electrons involved in reductions were obtained by controlled potential electrolyses of the isomers.展开更多
In this paper the heteropoly complexes K_n[Ga(H_20)MW_(11)O_39)]·xH_20 [M=Cu(Ⅱ), Co(Ⅱ), Cr(Ⅲ), Fe(Ⅲ), Mn(Ⅳ)] have been prepared in this laboratory firstly. The products were characterized by chemical analysi...In this paper the heteropoly complexes K_n[Ga(H_20)MW_(11)O_39)]·xH_20 [M=Cu(Ⅱ), Co(Ⅱ), Cr(Ⅲ), Fe(Ⅲ), Mn(Ⅳ)] have been prepared in this laboratory firstly. The products were characterized by chemical analysis, ionexchange, IR, UV and X-ray powder diffraction.展开更多
The heteropoly complexes K_(13)[Ln(GeW_9Mo_2O_(39))_2] centre dot nH_2O (Ln =La, Ce, Pr, Nd, and Sm) were prepared for the first time and characterized by chemical analysis,infrared (IR) spectrum, ultraviolet (UV) spe...The heteropoly complexes K_(13)[Ln(GeW_9Mo_2O_(39))_2] centre dot nH_2O (Ln =La, Ce, Pr, Nd, and Sm) were prepared for the first time and characterized by chemical analysis,infrared (IR) spectrum, ultraviolet (UV) spectrum, X-ray powder diffraction, and thermal analysis.IR, UV spectra, and X-ray powder diffraction studies show that the structure of the heteropolycomplexes is a square antiprism consisting of eight oxygen atoms of two GeW_9Mo_2O_(39)^(8-)heteropolyanions and a lanthanide ion. The thermostability of heteropoly complexes is lower thanthat of saturated Keggin structure dodecatungstogermanate.展开更多
The title compound was synthesized by means of direction. Its composition was determined by TG and ICP. The studies of IR and XRD indicate that the compound has the Keggin structure. The rare earth chemical thermal di...The title compound was synthesized by means of direction. Its composition was determined by TG and ICP. The studies of IR and XRD indicate that the compound has the Keggin structure. The rare earth chemical thermal diffusion of the complex also was studied. The results show that the rare earth element Gd can permeate into the surface, interface and the body cavity of the prepared material. The results of TG-DTA show that the stable temperature is improved and the conductivity of the permeated sample is 3.05 S·cm -1, which is 4.67×106 times higher than that of the parent K_7[BNi(OH_2)W_ 11O_ 39]·11H_2O.展开更多
文摘The present paper covers seven rare earth-containing tungstosilicate heteropoly complexes LnHSiW_(12)O_(40)·xH_2O with Keggin structure(Ln=La,Ce,Pr,Nd,Sm,Eu and Gd)snythesized by double decomposition reaction.The synthesized heteropoly complexes were characterized by ICP,^(29)Si-NMR,XPS, XRD,IR,UV,polarogram,CV and TG-DTA.The relationship between the structure of the synthesized heteropoly complexes and their properties is discussed.
文摘The capability of the synthesized heteropoly complexes of rare earths {K10 [(O39W11Si) Ln(Gly)3Ln(SiW11O39)]?H2O (Ln=La, Pr, Nd, Sm, Eu, Gd, Tb, Dy)} as the catalyst promoter in the synthesis of the ethyl acetate was studied. The results showed that the quantity of H2SO4 used for synthesizing the ethyl acetate can be reduced by 75% and the yield reached 98% at the optional condition.
文摘New indium heteropoly undecatungstometalate complexes of general formula K_n In( H_2O) MW_(11)O_(39) .xH_2O (M = Cr(Ⅲ) , Fe( Ⅲ ), Co(Ⅱ) or Zn( Ⅱ) ) were prepared by the stepwise acidification and the stepwise addition of materials. The products were characterized by elemental analysis, ion-exchange, IRspectra, UV spectra, X-ray powder diffraction and thermal analysis. The results show that the structure ofthe products derives from the Keggin structure. Their themial stability is higher than that of the homolo-gous dedecatungstometalates .
文摘Lanthanide heteropoly compounds K15[Ln(HSiW9O34)2]·28H2O(Ln = La, Ce, Nd), denoted as Ln(SiW9)2, were synthesized and characterized by element analysis, TG-DTA, IR, UV, XPS and XRD. The results show that partial oxygen in Ln(SiW9)2 was coordinated with Ln3- , where Ln-3 was in the inner side of the heteropoly anions, while the fundamental structure of SiW9 had little change. The result was supported by ion exchange experiment.
文摘The title complexes KaHb[M(SiW9O34)2]?mH2O(M=Ni,Cu,Zn,Fe or Mn) were synthesized by SiW9O34 10? with transition metal respectively and their structure were characterized by mean of elemental analysis, TG-DTA, IR spectra and, UV spectra. In addition, their redox properties in solution were investigated using polarographic and cyclic voltammographic methods. Experimental results indicated that the complexes have Keggin structure and that the heteropolyanions underwent two-step, two-electron tungsten reduction processes.
文摘Seven new-type pentabasic heteropoly complexes with the general molecular formula K 10H 5[Ln(PMo 5W 4V 2O 39) 2]·nH 2O(Ln=La, Ce, Pr, Nd, Eu, Gd, Dy) were synthesized. The results of IR, UV, 31P, 51V NMR and X-ray powder diffraction pattern demonstrate that the product still maintains Keggin structure. The thermal stability studied by water solubility test, TG-DTA, XRD and IR at various temperature shows that the range of pyrolysis temperature is from 500～550 ℃. The catalytic action varies according to the contents of rare earths which are used to catalyze the decomposition of hydrogen peroxide.
基金This project was supported by the National Natural Science Foundation of China.
文摘Eight new compounds of α- and β- M2H4[SiW16Cr2(OH2)2O ] .xH2O types, where M = K, Me4N, Et4N or n-Bu4N, and 0+6=6,were synthesized from trivacant heteropoly tungstate α-and β-[SiW9O34]10 precursors, and characterized by elemental analysis, thermal gravimetric analysis, IR, UV-visible spectra, X-ray photoelectron spectroscopy(XPS), polarography, magnetic measurements and X-ray powder diffraction. The IR and UV spectra conJEirm that α-and β-[SlW10Cr2(OH2)2O24]6- isomers possess α-and β-Keg-gin structures. The differences between α-and β-isomers in IR, UV spectra and polarography are discussed.
基金Supported by the National Natural Science Foundation of China.
文摘Heteropoly-complexes K17[Ln(CuW11O39)2].xH2O(Ln = La, Ce, Pr, Nd, Sm, Eu, Gd, Dy) were prepared. The properties of the products were investigated by ion-exchange, conductometric titration, IR, UV and X-ray powder diffraction. The results show that the structure of the products is similar to that of U(a-Ge11O39)2 and consistent with the model proposed by Peacock.
文摘Two new compounds of A- type α-and β-K4.5H2.5[SiW9Cr3(OH2)3O37]·xH2O were synthesized. The two kinds of isomers of α-and β-SiW12-xCrx(x=2, 3) were identified by Second-derivative IR spectroscopy and cyclic voltammetry. The numbers of electrons involved in reductions were obtained by controlled potential electrolyses of the isomers.
文摘In this paper the heteropoly complexes K_n[Ga(H_20)MW_(11)O_39)]·xH_20 [M=Cu(Ⅱ), Co(Ⅱ), Cr(Ⅲ), Fe(Ⅲ), Mn(Ⅳ)] have been prepared in this laboratory firstly. The products were characterized by chemical analysis, ionexchange, IR, UV and X-ray powder diffraction.
基金This work was financially supported by the National Natural Science Foundation(No.20271045)of China and China Post doctoral Science Foundation.
文摘The heteropoly complexes K_(13)[Ln(GeW_9Mo_2O_(39))_2] centre dot nH_2O (Ln =La, Ce, Pr, Nd, and Sm) were prepared for the first time and characterized by chemical analysis,infrared (IR) spectrum, ultraviolet (UV) spectrum, X-ray powder diffraction, and thermal analysis.IR, UV spectra, and X-ray powder diffraction studies show that the structure of the heteropolycomplexes is a square antiprism consisting of eight oxygen atoms of two GeW_9Mo_2O_(39)^(8-)heteropolyanions and a lanthanide ion. The thermostability of heteropoly complexes is lower thanthat of saturated Keggin structure dodecatungstogermanate.
文摘The title compound was synthesized by means of direction. Its composition was determined by TG and ICP. The studies of IR and XRD indicate that the compound has the Keggin structure. The rare earth chemical thermal diffusion of the complex also was studied. The results show that the rare earth element Gd can permeate into the surface, interface and the body cavity of the prepared material. The results of TG-DTA show that the stable temperature is improved and the conductivity of the permeated sample is 3.05 S·cm -1, which is 4.67×106 times higher than that of the parent K_7[BNi(OH_2)W_ 11O_ 39]·11H_2O.
