： The four heteropoly isomers K3H2[α-,β i-SiW11Fe(H2O)O39]· xH2O(β i=β 1,β 2,β 3)were prepared and Characterized by elementary analysis, IR and UV Spectroscopy. Its electrochemical behavior in aqueous solu...： The four heteropoly isomers K3H2[α-,β i-SiW11Fe(H2O)O39]· xH2O(β i=β 1,β 2,β 3)were prepared and Characterized by elementary analysis, IR and UV Spectroscopy. Its electrochemical behavior in aqueous solution has been discussed. The order of Polarographic half-wave potential E1/2 of heteropoly anions is as follows:β 2 >β 1 >β 3 >α . Its reduction process involves an one-electron reduction of Fe? and a pair of two-electron reduction of W? . Epolidation of maleic acid with H2O2 Catalyzed by heteropoly positional isomers was studied.β 3 isomers are the most active.展开更多
The four heteropoly isomers K3H3[α ,β i SiW11Zn(H2O)O39]· XH2O(β i=β 1,β 2,β 3) were prepared and characterized by elementary analysis, IR and UV spectroscopy, polargraphy and cyclic voitammetry, 183W NMR a...The four heteropoly isomers K3H3[α ,β i SiW11Zn(H2O)O39]· XH2O(β i=β 1,β 2,β 3) were prepared and characterized by elementary analysis, IR and UV spectroscopy, polargraphy and cyclic voitammetry, 183W NMR and XPS experiments. And these compounds can catalyze epoxidation reaction of olefine.展开更多
The thermal properties of two heteropoly complexes a- [ (C7H15) 4N]3H2[SiW11 (NbO2) O39] H2O and a-[ (C7H15)4N]4 [PW11 (NbO2). O39] H2O were studied by means of TG DTA and DSC. The activation energies and reaction ord...The thermal properties of two heteropoly complexes a- [ (C7H15) 4N]3H2[SiW11 (NbO2) O39] H2O and a-[ (C7H15)4N]4 [PW11 (NbO2). O39] H2O were studied by means of TG DTA and DSC. The activation energies and reaction orders of the thermal decomposition reaction of these complexes have been calculated.展开更多
The eight heteropoly complexes M4H2[PW9（NbO2）3O37]·xH2O和M4-mHm[PW11（NbO2）O39]·xH2O(M=Me4N+（TMA）,Bu4N+（TBA）,Et4N+（TEA）,He4H+（THA）were synthesized and characterized by IR,UV spectrometry,polarogra...The eight heteropoly complexes M4H2[PW9（NbO2）3O37]·xH2O和M4-mHm[PW11（NbO2）O39]·xH2O(M=Me4N+（TMA）,Bu4N+（TBA）,Et4N+（TEA）,He4H+（THA）were synthesized and characterized by IR,UV spectrometry,polarography and 183W NMR spectra.The experimantal results indicated that they were all the Keggin structure and the reduced electric potential of the complexes arised over-0.3 with entering of NbO2 groups.Experiments on oxidation of maleic acid into tartaric acid showed that the complexes containing peroxo ions exhibited higher catalytic activity than those without peroxo ions.The catalytic activity of heteropoly complexes with（NbO2）3 was higher than that of heteropoly complexes with（NbO2）.展开更多
文摘： The four heteropoly isomers K3H2[α-,β i-SiW11Fe(H2O)O39]· xH2O(β i=β 1,β 2,β 3)were prepared and Characterized by elementary analysis, IR and UV Spectroscopy. Its electrochemical behavior in aqueous solution has been discussed. The order of Polarographic half-wave potential E1/2 of heteropoly anions is as follows:β 2 >β 1 >β 3 >α . Its reduction process involves an one-electron reduction of Fe? and a pair of two-electron reduction of W? . Epolidation of maleic acid with H2O2 Catalyzed by heteropoly positional isomers was studied.β 3 isomers are the most active.
文摘The four heteropoly isomers K3H3[α ,β i SiW11Zn(H2O)O39]· XH2O(β i=β 1,β 2,β 3) were prepared and characterized by elementary analysis, IR and UV spectroscopy, polargraphy and cyclic voitammetry, 183W NMR and XPS experiments. And these compounds can catalyze epoxidation reaction of olefine.
文摘The thermal properties of two heteropoly complexes a- [ (C7H15) 4N]3H2[SiW11 (NbO2) O39] H2O and a-[ (C7H15)4N]4 [PW11 (NbO2). O39] H2O were studied by means of TG DTA and DSC. The activation energies and reaction orders of the thermal decomposition reaction of these complexes have been calculated.
文摘The eight heteropoly complexes M4H2[PW9（NbO2）3O37]·xH2O和M4-mHm[PW11（NbO2）O39]·xH2O(M=Me4N+（TMA）,Bu4N+（TBA）,Et4N+（TEA）,He4H+（THA）were synthesized and characterized by IR,UV spectrometry,polarography and 183W NMR spectra.The experimantal results indicated that they were all the Keggin structure and the reduced electric potential of the complexes arised over-0.3 with entering of NbO2 groups.Experiments on oxidation of maleic acid into tartaric acid showed that the complexes containing peroxo ions exhibited higher catalytic activity than those without peroxo ions.The catalytic activity of heteropoly complexes with（NbO2）3 was higher than that of heteropoly complexes with（NbO2）.
