A novel halogen-free phosphorus–nitrogen–silicon flame retardant monomer with reactive siloxy groups,N-(diphenylphosphino)-1,1-diphenyl-N-(3-(triethoxysilyl)propyl) phosphinamine(DPTA) has been synthesized and was a...A novel halogen-free phosphorus–nitrogen–silicon flame retardant monomer with reactive siloxy groups,N-(diphenylphosphino)-1,1-diphenyl-N-(3-(triethoxysilyl)propyl) phosphinamine(DPTA) has been synthesized and was applied to the fire-resistant finishing of cotton fabrics. The molecular structure of DPTA has been well characterized by elemental analysis, FTIR,1H NMR, and ^(31)P NMR spectroscopies. The chemically-grafted cotton fabrics, which were treated with 25 wt% DPTA, were obtained and confirmed by attenuated total reflectance Fourier infrared spectroscopy(ATR-FTIR). The flame retardancy and thermal property of the treated samples were investigated by limited oxygen index(LOI), vertical flammability test(VFT), thermogravimetric analysis(TGA) and microscale combustion calorimeter(MCC). It is noted that in vertical flammability test, the treated samples extinguished immediately upon removing the ignition source, whereas the untreated one was completely burned out. Furthermore, TGA and MCC tests revealed that the treated samples produced a high char formation and a low heated release during combustion. The surface morphology of the untreated and treated samples and the char residues after LOI tests were observed by scanning electron microscopy(SEM). Therefore, all the results showed that the treated cotton fabrics with 25 wt% DPTA apparently improved the fireresistant and thermal performances.展开更多
The mass spectrometry of gold clusters stabilized by poly（N‐vinyl‐2‐pyrrolidone） （Au：PVP） re‐vealed the presence of Cl adsorbates derived from synthetic precursors, mainly on the Au34 and Au43 clusters. Chang...The mass spectrometry of gold clusters stabilized by poly（N‐vinyl‐2‐pyrrolidone） （Au：PVP） re‐vealed the presence of Cl adsorbates derived from synthetic precursors, mainly on the Au34 and Au43 clusters. Changes in the amount of Cl adsorbates on the Au clusters did not affect the catalytic prop‐erties for the aerobic oxidation of benzyl alcohol, suggesting that the Cl atoms were only weakly bound to the Au clusters. In contrast, the replacement of Cl with Br on the Au34 and Au43 clusters significantly suppressed activity, without any influence on the electronic structure. This result indi‐cated that the Br atoms were strongly bound to the Au clusters and sterically blocked their active sites. The substantial reduction of the catalytic activity by the Br adsorbates suggested that the Au34 and Au43 clusters made a major contribution to the catalytic activity of the Au：PVP.展开更多
Synthesis of organosilanes from alkenes is a very important topic owing to their wide applications.A Ni/Cu dual metal-catalyzed arylsilylation of terminal alkenes,featuring migratory selectivity,has been developed.A w...Synthesis of organosilanes from alkenes is a very important topic owing to their wide applications.A Ni/Cu dual metal-catalyzed arylsilylation of terminal alkenes,featuring migratory selectivity,has been developed.A wide diversity of aliphatic silanes have been prepared from terminal alkenes,aryl halides and Suginome’s reagent.This protocol is highlighted by excellent regioselectivity,mild reaction conditions and good functional group tolerance.In addition to benzylic positions,carbon–carbon bonds can also be constructed at allylic positions.Preliminary mechanistic studies suggest that the copper cocatalyst promotes the transmetalation of Suginome’s reagent,and the addition of a Pyr Ox ligand inhibits the formation of side-products from the carbon-Heck pathway.Moreover,studies toward the nature of the Pyr Ox ligand revealed that the steric hindrance of the oxazoline moiety greatly affects the chain–walking process,but not the arylation step.展开更多
基金Supported by the National Natural Science Foundation of China(21301160)
文摘A novel halogen-free phosphorus–nitrogen–silicon flame retardant monomer with reactive siloxy groups,N-(diphenylphosphino)-1,1-diphenyl-N-(3-(triethoxysilyl)propyl) phosphinamine(DPTA) has been synthesized and was applied to the fire-resistant finishing of cotton fabrics. The molecular structure of DPTA has been well characterized by elemental analysis, FTIR,1H NMR, and ^(31)P NMR spectroscopies. The chemically-grafted cotton fabrics, which were treated with 25 wt% DPTA, were obtained and confirmed by attenuated total reflectance Fourier infrared spectroscopy(ATR-FTIR). The flame retardancy and thermal property of the treated samples were investigated by limited oxygen index(LOI), vertical flammability test(VFT), thermogravimetric analysis(TGA) and microscale combustion calorimeter(MCC). It is noted that in vertical flammability test, the treated samples extinguished immediately upon removing the ignition source, whereas the untreated one was completely burned out. Furthermore, TGA and MCC tests revealed that the treated samples produced a high char formation and a low heated release during combustion. The surface morphology of the untreated and treated samples and the char residues after LOI tests were observed by scanning electron microscopy(SEM). Therefore, all the results showed that the treated cotton fabrics with 25 wt% DPTA apparently improved the fireresistant and thermal performances.
基金supported by the Elements Strategy Initiative for Catalysts and Batteries (ESICB)a Grant-in-Aid for Scientific Research (26248003, 15H01042) from the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan
文摘The mass spectrometry of gold clusters stabilized by poly（N‐vinyl‐2‐pyrrolidone） （Au：PVP） re‐vealed the presence of Cl adsorbates derived from synthetic precursors, mainly on the Au34 and Au43 clusters. Changes in the amount of Cl adsorbates on the Au clusters did not affect the catalytic prop‐erties for the aerobic oxidation of benzyl alcohol, suggesting that the Cl atoms were only weakly bound to the Au clusters. In contrast, the replacement of Cl with Br on the Au34 and Au43 clusters significantly suppressed activity, without any influence on the electronic structure. This result indi‐cated that the Br atoms were strongly bound to the Au clusters and sterically blocked their active sites. The substantial reduction of the catalytic activity by the Br adsorbates suggested that the Au34 and Au43 clusters made a major contribution to the catalytic activity of the Au：PVP.
基金supported by the National Natural Science Foundation of China(21702151,21774029,and 21871211)the Fundamental Research Funds for Central Universities(2042019kf0208)。
文摘Synthesis of organosilanes from alkenes is a very important topic owing to their wide applications.A Ni/Cu dual metal-catalyzed arylsilylation of terminal alkenes,featuring migratory selectivity,has been developed.A wide diversity of aliphatic silanes have been prepared from terminal alkenes,aryl halides and Suginome’s reagent.This protocol is highlighted by excellent regioselectivity,mild reaction conditions and good functional group tolerance.In addition to benzylic positions,carbon–carbon bonds can also be constructed at allylic positions.Preliminary mechanistic studies suggest that the copper cocatalyst promotes the transmetalation of Suginome’s reagent,and the addition of a Pyr Ox ligand inhibits the formation of side-products from the carbon-Heck pathway.Moreover,studies toward the nature of the Pyr Ox ligand revealed that the steric hindrance of the oxazoline moiety greatly affects the chain–walking process,but not the arylation step.
