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活性炭负载壳聚糖络合铂配合物催化硅氢加成反应 总被引:1,自引:0,他引:1
以活性炭为载体,将壳聚糖(CS)负载到活性炭上得到复合载体,利用CS对Pt的螯合作用,制备活性炭负载CS络合Pt配合物催化剂(AC—CS—Pt),并考察了AC—CS—Pt催化剂催化烯烃与三乙氧基硅烷加成反应性能。采用X-射线衍射(XRD)、红外光谱(IR)和热重分析(TG)对AC—CS—Pt进行了表征,结果表明Pt与CS氨基N原子配位形成Pt—N配位键。对辛烯硅氢加成反应,AC—CS—Pt催化剂显示高活性和极好的产物选择性,β-加成产物的选择性达99%;具有良好的重复使用性能,AC—CS—Pt催化剂经简单过滤分离后,可连续使用14次而活性没有明显下降。 相似文献
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对二烷基咪唑类离子液体作为烯烃与三乙氧基氢硅烷硅氢加成反应的介质进行了研究.研究发现,二烷基咪唑类离子液体组成的阴、阳离子不同对烯烃与三乙氧基氢硅烷的反应有一定影响.离子液体为二烷基咪唑六氟磷酸盐时,咪唑环上取代烷基链长的增加,苯乙烯和三乙氧基氢硅烷加成反应中β加成物/α加成物的比值也随之增加.同时,二烷基咪唑类离子液体的阴离子件质也亢接影响了硅氢加成反应的发生.以[Bmim]PF6作为反应溶剂,反应完成后,离子液体催化剂体系可以比较容易地与产物分离,并可以重复使用. 相似文献
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通过活性炭负载铂制备了一种硅氢加成反应用多相催化剂(Pt/C),考察了活性炭处理、还原pH值、催化剂铂负载量、反应时间对Pt/C催化苯乙烯与三乙氧基硅烷加成反应催化性能的影响.结果表明:用15%硝酸处理活性炭载体,pH值为8.5环境下还原的负载量为5%的Pt/C催化剂具有最好的催化效果,苯乙烯转换率为100%,β-加成产物选择性为94.9%. 相似文献
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A series of carboxylated long chain polyethylene glycols(abbreviated as PEGCOOH) has been synthesized and used to support chloroplatinic acid.These supported catalysts were then tested for their efficiency in the hydrosilylation of alkenes.The factors affecting their catalytic properties,e.g.relative molecular mass of polyethylene glycol,reaction temperature,platinum content,and type of alkenes,have been studied.It was found that the activity of the platinum catalyst decreased with increasing length of the polyethylene glycol chain,and increased with reaction temperature.Moreover,these catalysts could be reused several times without a noticeable decrease in activity or selectivity.The reaction pathway leading to excellent selectivity for the β-adduct of hydrosilylation of alkenes with triethoxysilane catalyzed by this catalysis system was discussed. 相似文献
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A series of aromatic acids has been tested as additives for the platinum-catalyzed hydrosilylation of styrene with triethoxysilane. Both excellent conversion of styrene and selectivity in favor of the β-adduct were achieved using aminobenzoic acids as additive. Moreover, the use of 4-aminobenzoic acid led to significantly superior enhancement in both catalytic activity and selectivity among the tested aminobenzoic acids. Indeed, 100% conversion of styrene and 98.4% selectivity in favor of the β-adduct were obtained. Additionally, hydrosilylations of various alkenes with a variety of platinum catalysts have also been tested, and in each case the conversion of substrate and the selectivity of the β-adduct were promoted by using 4-aminobenzoic acid as additive. 相似文献
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