研究了2-甲基-2-全氟-2'-甲基-3'-氧代己酰氧基乙氧基羰基乙基甲基二聚氧乙烯基硅烷(Ⅴ)的制备方法和表面活性。以甲基丙烯酸-2-全氟-2'-甲基-3'-氧代己酰氧基乙基酯(Ⅰ)和甲基二氯硅烷(Ⅱ)为原料,0.5%Karsted催化剂存...研究了2-甲基-2-全氟-2'-甲基-3'-氧代己酰氧基乙氧基羰基乙基甲基二聚氧乙烯基硅烷(Ⅴ)的制备方法和表面活性。以甲基丙烯酸-2-全氟-2'-甲基-3'-氧代己酰氧基乙基酯(Ⅰ)和甲基二氯硅烷(Ⅱ)为原料,0.5%Karsted催化剂存在下(以Ⅰ的质量计),发生硅氢化反应,得到2-甲基-2-全氟-2'-甲基-3'-氧代己酰氧基乙氧基羰基乙基甲基二氯硅烷(Ⅲ)。Ⅲ与聚乙二醇(Ⅳ)缩合反应得到非离子表面活性剂Ⅴ。用FTIR和MS对其结构进行了表征,优化了硅氢化反应工艺条件,测试了Ⅴ溶液的表面张力、临界胶束浓度(CMC)和处理玻璃后的疏水性能。以四氢呋喃为溶剂,中间体Ⅲ的较优合成条件为:n(Ⅰ)∶n(Ⅱ)=1.2∶1,50℃下反应28 h,化合物Ⅱ的转化率可达到68.2%。表面活性剂Ⅴ水溶液的CMC为0.52 g/L,临界表面张力γ_(CMC)为22.8 m N/m,用V的THF溶液处理玻璃后,玻璃表面具有很好的疏水性和较好的疏油性。展开更多
Nineβ‐cyclodextrin derivatives containing an amino group were synthesized via nucleophilic sub‐stitution from mono（6‐O‐p‐tolylsulfonyl）‐β‐cyclodextrin and used in asymmetric biomimetic Mi‐chael addition re...Nineβ‐cyclodextrin derivatives containing an amino group were synthesized via nucleophilic sub‐stitution from mono（6‐O‐p‐tolylsulfonyl）‐β‐cyclodextrin and used in asymmetric biomimetic Mi‐chael addition reactions in water at room temperature. The mechanism responsible for the moder‐ate activity and enantioselectivity of the β‐cyclodextrin derivatives was explored using nuclear magnetic resonance spectroscopy, namely 2D 1H rotating‐frame overhauser effect spectroscopy （ROESY）, ultraviolet absorption spectroscopy, and quantum chemical calculations, which provide a useful technique for investigating the formation of inclusion complexes. The effects of the pH of the reaction medium, theβ‐cyclodextrin derivative dosage, the structure of the modifying amino group, and various substrates on the yield and enantioselectivity were investigated. The results indicated that these factors had an important effect on the enantiomeric excess （ee） in the reaction system. Experiments using a competitor for inclusion complex formation showed that a hydrophobic cavity is necessary for enantioselective Michael addition. A comparison of the reactions using 4‐nitro‐β‐nitrostyrene and 2‐nitro‐β‐nitrostyrene showed that steric hindrance improved the enan‐tioselectivity. This was verified by the optimized geometries obtained from quantum chemical cal‐culations. An ee of 71%was obtained in the asymmetric Michael addition of cyclohexanone and 2‐nitro‐β‐nitrostyrene, using （S）‐2‐aminomethylpyrrolidine‐modified β‐CD as the catalyst, in an aqueous buffer solution, i.e., CH3COONa‐HCl （pH 7.5）.展开更多
针对纺织品中全氟辛酸(PFOA)的样品预处理,采用液相色谱-串联质谱法测定纺织品中的PFOA,引入超声波萃取技术,对纺织品中的PFOA的萃取剂、超声波频率、萃取时间、萃取次数等萃取条件进行研究。结果表明,优化的萃取条件为:在40℃、28 k H...针对纺织品中全氟辛酸(PFOA)的样品预处理,采用液相色谱-串联质谱法测定纺织品中的PFOA,引入超声波萃取技术,对纺织品中的PFOA的萃取剂、超声波频率、萃取时间、萃取次数等萃取条件进行研究。结果表明,优化的萃取条件为:在40℃、28 k Hz超声波辅助下,用甲醇作为萃取剂,萃取30 min,萃取3次,PFOA的回收率可以达到98.56%。展开更多
文摘研究了2-甲基-2-全氟-2'-甲基-3'-氧代己酰氧基乙氧基羰基乙基甲基二聚氧乙烯基硅烷(Ⅴ)的制备方法和表面活性。以甲基丙烯酸-2-全氟-2'-甲基-3'-氧代己酰氧基乙基酯(Ⅰ)和甲基二氯硅烷(Ⅱ)为原料,0.5%Karsted催化剂存在下(以Ⅰ的质量计),发生硅氢化反应,得到2-甲基-2-全氟-2'-甲基-3'-氧代己酰氧基乙氧基羰基乙基甲基二氯硅烷(Ⅲ)。Ⅲ与聚乙二醇(Ⅳ)缩合反应得到非离子表面活性剂Ⅴ。用FTIR和MS对其结构进行了表征,优化了硅氢化反应工艺条件,测试了Ⅴ溶液的表面张力、临界胶束浓度(CMC)和处理玻璃后的疏水性能。以四氢呋喃为溶剂,中间体Ⅲ的较优合成条件为:n(Ⅰ)∶n(Ⅱ)=1.2∶1,50℃下反应28 h,化合物Ⅱ的转化率可达到68.2%。表面活性剂Ⅴ水溶液的CMC为0.52 g/L,临界表面张力γ_(CMC)为22.8 m N/m,用V的THF溶液处理玻璃后,玻璃表面具有很好的疏水性和较好的疏油性。
基金supported by the National Natural Science Foundation of China (21425627,21376279)~~
文摘Nineβ‐cyclodextrin derivatives containing an amino group were synthesized via nucleophilic sub‐stitution from mono（6‐O‐p‐tolylsulfonyl）‐β‐cyclodextrin and used in asymmetric biomimetic Mi‐chael addition reactions in water at room temperature. The mechanism responsible for the moder‐ate activity and enantioselectivity of the β‐cyclodextrin derivatives was explored using nuclear magnetic resonance spectroscopy, namely 2D 1H rotating‐frame overhauser effect spectroscopy （ROESY）, ultraviolet absorption spectroscopy, and quantum chemical calculations, which provide a useful technique for investigating the formation of inclusion complexes. The effects of the pH of the reaction medium, theβ‐cyclodextrin derivative dosage, the structure of the modifying amino group, and various substrates on the yield and enantioselectivity were investigated. The results indicated that these factors had an important effect on the enantiomeric excess （ee） in the reaction system. Experiments using a competitor for inclusion complex formation showed that a hydrophobic cavity is necessary for enantioselective Michael addition. A comparison of the reactions using 4‐nitro‐β‐nitrostyrene and 2‐nitro‐β‐nitrostyrene showed that steric hindrance improved the enan‐tioselectivity. This was verified by the optimized geometries obtained from quantum chemical cal‐culations. An ee of 71%was obtained in the asymmetric Michael addition of cyclohexanone and 2‐nitro‐β‐nitrostyrene, using （S）‐2‐aminomethylpyrrolidine‐modified β‐CD as the catalyst, in an aqueous buffer solution, i.e., CH3COONa‐HCl （pH 7.5）.
文摘针对纺织品中全氟辛酸(PFOA)的样品预处理,采用液相色谱-串联质谱法测定纺织品中的PFOA,引入超声波萃取技术,对纺织品中的PFOA的萃取剂、超声波频率、萃取时间、萃取次数等萃取条件进行研究。结果表明,优化的萃取条件为:在40℃、28 k Hz超声波辅助下,用甲醇作为萃取剂,萃取30 min,萃取3次,PFOA的回收率可以达到98.56%。
