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
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
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).
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.