The effect of the functionallization of POMs on their properties was examined by the comparison between both titanium and its corresponding cyclopentadienyl subsituted polyoxocomplexes. The polarographic half wave po...The effect of the functionallization of POMs on their properties was examined by the comparison between both titanium and its corresponding cyclopentadienyl subsituted polyoxocomplexes. The polarographic half wave potential of the complexes indicated that the effect of the functionallization of POMs increased the oxidizing ability of the polyoxoanions. The inhibitory effects of the CpTi polyoxocomplexes on tumor cells are higher than those of the corresponding titanium polyoxocomplexes, and the toxicity of the former is lower than that of the latter. The oxygenation reactions of cyclohexene, styrene, trans stilbene and maleic acid with PhIO or hydrogen peroxide(30% aqueous solution) catalyzed respectively by Ti and CpTi polyoxocomplexes were compared.展开更多
One new sandwich-type tetra-nickel substituted polyoxotungsate,[Ni（trien）]4-[Ni4（H2O）2（HPW9O34）2]·4H2O（1,trien=triethylenetetramine）,has been hydrothermally synthesized and characterized by IR,elemental a...One new sandwich-type tetra-nickel substituted polyoxotungsate,[Ni（trien）]4-[Ni4（H2O）2（HPW9O34）2]·4H2O（1,trien=triethylenetetramine）,has been hydrothermally synthesized and characterized by IR,elemental analysis,TGA,and single-crystal X-ray diffraction analysis.Crystal data for 1：triclinic,space group P with a=13.279（3）,b=13.816（3）,c=14.494（4）,α=95.403（1）,β=113.173（4）,γ=93.809（3）o,V=2418.0（10）3,Z=1 and Dc=3.861 g/cm3.X-ray crystallographic study shows that compound 1 is a relatively rare inorganic-organic hybrid polyoxo tungstate constructed from sandwich Ni-substituted polyoxo-anions and nickel complexes.展开更多
In this work, we report the tuning effect of the Si substitution on the magnetic and high frequency electromagnetic properties of R2 Fe17 compounds and their paraffin composites. It is found that the introduction of S...In this work, we report the tuning effect of the Si substitution on the magnetic and high frequency electromagnetic properties of R2 Fe17 compounds and their paraffin composites. It is found that the introduction of Si can remarkably improve the magnetic and electromagnetic properties of the R2 Fe17 compounds, making the R2 Fe17 exSix-paraffin composites excellent microwave absorption materials(MAMs). By introducing the Si element, their saturation magnetizations decrease slightly, while much higher Curie temperatures are obtained. Furthermore, better impedance match is reached due to the decrease of the high-frequency permittivity ε’ by about 40%e50%, which finally enhances the performance of the microwave absorption. The peak frequency(fRL) of the reflection loss(RL) curve moves toward high frequency domain and the qualified bandwidth(QB, RL≤-10 dB) increases remarkably. The maximum QB of 3.3 GHz(12.0 e15.3 GHz) is obtained for the Sm1.5 Y0.5 Fe15 Si2-paraffin composite(d = 1.0 mm) and the maximum RL of -53.6 dB is achieved for Nd2 Fe15 Si2-paraffin composite(d = 2.2 mm), both surpassing most of the reported MAMs. Additionally, a distinguished dielectric microwave absorption peak is observed, which further increases the QB in these composites.展开更多
Gdo.9xRxEUo.lOOH （R=Y, La） crystals were synthesized by a flux method using a mixture of NaOH and KOH as the flux. X-ray diffraction data were well refined using the Rietveld method assuming that the crystals had a ...Gdo.9xRxEUo.lOOH （R=Y, La） crystals were synthesized by a flux method using a mixture of NaOH and KOH as the flux. X-ray diffraction data were well refined using the Rietveld method assuming that the crystals had a monoclinic structre belonging to the P21/m space group. The unit cell volumes of the Gdo.9 xLaxEuo.OOH crystals increased with increasing x, whereas those of Gdo.9-xYxEUo.lOOH decreased with increasing x. The Commission Internationale de IEclairage （CIE） chromaticity coordinates of Gdo.9 xRxEUo.lOOH （R=Y, La） crystals were located in the red region and were nearly constant over the range ofx values considered. The fluorescence quantum yield Dr monotonically decreased with increasing x regardless of the ionic radii of the substitute ions. The fact that the Dr value of Lao.9EuoAOOH was greater than that of Gdo.gEUo.lOOH indicated that the observed decrease in the values of the Gdo.9-,LaxEuo.1OOH crystals up to x=0.3 could not be attributed to an increase in the distance between Eu3＋ ions or to a decrease in the Gd3＋ content. The decrease might be due to an increase of killer centers introduced by elemental substitutions with the larger ion.展开更多
基金Supported by the National Natural Science Foundation of China(No.39970 82 4 )
文摘The effect of the functionallization of POMs on their properties was examined by the comparison between both titanium and its corresponding cyclopentadienyl subsituted polyoxocomplexes. The polarographic half wave potential of the complexes indicated that the effect of the functionallization of POMs increased the oxidizing ability of the polyoxoanions. The inhibitory effects of the CpTi polyoxocomplexes on tumor cells are higher than those of the corresponding titanium polyoxocomplexes, and the toxicity of the former is lower than that of the latter. The oxygenation reactions of cyclohexene, styrene, trans stilbene and maleic acid with PhIO or hydrogen peroxide(30% aqueous solution) catalyzed respectively by Ti and CpTi polyoxocomplexes were compared.
基金supported by the National Natural Science Fund for Distinguished Young Scholars of China (No 20725101)the 973 Program (No 2006CB932904)+2 种基金the NSF of Fujian Province (No E0510030)the NNSFC (No 20521101)the Research Foundation of Education Bureau of Fujian Province (No JA08053)
文摘One new sandwich-type tetra-nickel substituted polyoxotungsate,[Ni（trien）]4-[Ni4（H2O）2（HPW9O34）2]·4H2O（1,trien=triethylenetetramine）,has been hydrothermally synthesized and characterized by IR,elemental analysis,TGA,and single-crystal X-ray diffraction analysis.Crystal data for 1：triclinic,space group P with a=13.279（3）,b=13.816（3）,c=14.494（4）,α=95.403（1）,β=113.173（4）,γ=93.809（3）o,V=2418.0（10）3,Z=1 and Dc=3.861 g/cm3.X-ray crystallographic study shows that compound 1 is a relatively rare inorganic-organic hybrid polyoxo tungstate constructed from sandwich Ni-substituted polyoxo-anions and nickel complexes.
基金Project supported by the National Key Research and Development Program of China(2016YFB0700901,2017YFA0403701)National Natural Science Foundation of China(51731001,11675006,11805006)
文摘In this work, we report the tuning effect of the Si substitution on the magnetic and high frequency electromagnetic properties of R2 Fe17 compounds and their paraffin composites. It is found that the introduction of Si can remarkably improve the magnetic and electromagnetic properties of the R2 Fe17 compounds, making the R2 Fe17 exSix-paraffin composites excellent microwave absorption materials(MAMs). By introducing the Si element, their saturation magnetizations decrease slightly, while much higher Curie temperatures are obtained. Furthermore, better impedance match is reached due to the decrease of the high-frequency permittivity ε’ by about 40%e50%, which finally enhances the performance of the microwave absorption. The peak frequency(fRL) of the reflection loss(RL) curve moves toward high frequency domain and the qualified bandwidth(QB, RL≤-10 dB) increases remarkably. The maximum QB of 3.3 GHz(12.0 e15.3 GHz) is obtained for the Sm1.5 Y0.5 Fe15 Si2-paraffin composite(d = 1.0 mm) and the maximum RL of -53.6 dB is achieved for Nd2 Fe15 Si2-paraffin composite(d = 2.2 mm), both surpassing most of the reported MAMs. Additionally, a distinguished dielectric microwave absorption peak is observed, which further increases the QB in these composites.
基金supported by Japan Society for the Promotion of Science(JSPS)KAKENHI Grants(2156069624560827)
文摘Gdo.9xRxEUo.lOOH （R=Y, La） crystals were synthesized by a flux method using a mixture of NaOH and KOH as the flux. X-ray diffraction data were well refined using the Rietveld method assuming that the crystals had a monoclinic structre belonging to the P21/m space group. The unit cell volumes of the Gdo.9 xLaxEuo.OOH crystals increased with increasing x, whereas those of Gdo.9-xYxEUo.lOOH decreased with increasing x. The Commission Internationale de IEclairage （CIE） chromaticity coordinates of Gdo.9 xRxEUo.lOOH （R=Y, La） crystals were located in the red region and were nearly constant over the range ofx values considered. The fluorescence quantum yield Dr monotonically decreased with increasing x regardless of the ionic radii of the substitute ions. The fact that the Dr value of Lao.9EuoAOOH was greater than that of Gdo.gEUo.lOOH indicated that the observed decrease in the values of the Gdo.9-,LaxEuo.1OOH crystals up to x=0.3 could not be attributed to an increase in the distance between Eu3＋ ions or to a decrease in the Gd3＋ content. The decrease might be due to an increase of killer centers introduced by elemental substitutions with the larger ion.
