CAJ | 학술논문

将高活性的硫钨杂多阴离子[SO4W2O10]2-(记为SW2)分别与四丁基铵阳离子([TBA]2SW2)、1-十二烷基-3-甲基咪唑阳离子([DMIM]2SW2)及质子化十二烷基咪唑阳离子([HDIM]2SW2)组合构筑了有效的烯烃环氧化催化剂体系.针对环辛烯的环氧化反应,比较了这3种催化剂的催化性能.研究发现在反应过程中,阳离子对催化剂活性中心的结构变化有显著的影响.当n(环辛烯)∶n(双氧水)=1∶1,乙酸乙酯作为反应介质时,[DMIM]2SW2、[HDIM]2SW2催化剂在反应完成后发生自分离现象,并且,催化剂在循环1次后的活性反而要高于新鲜催化剂的活性.这可能是由于反应过程中,双氧水促使高活性和高稳定性的催化中心的形成.重点研究了[HDIM]2SW2催化剂在乙酸乙酯介质中的反应性能以及催化循环效果,并表征了此催化剂在反应过程中的状态变化.
장고활성적류오잡다음리자[SO4W2O10]2-(기위SW2)분별여사정기안양리자([TBA]2SW2)、1-십이완기-3-갑기미서양리자([DMIM]2SW2)급질자화십이완기미서양리자([HDIM]2SW2)조합구축료유효적희경배양화최화제체계.침대배신희적배양화반응,비교료저3충최화제적최화성능.연구발현재반응과정중,양리자대최화제활성중심적결구변화유현저적영향.당n(배신희)∶n(쌍양수)=1∶1,을산을지작위반응개질시,[DMIM]2SW2、[HDIM]2SW2최화제재반응완성후발생자분리현상,병차,최화제재순배1차후적활성반이요고우신선최화제적활성.저가능시유우반응과정중,쌍양수촉사고활성화고은정성적최화중심적형성.중점연구료[HDIM]2SW2최화제재을산을지개질중적반응성능이급최화순배효과,병표정료차최화제재반응과정중적상태변화.
The ionic liquid-type compounds consisting of highly active oxoperoxosulfatometalate anions [SO4W2O10]2－(SW2 for short) and three different cations, namely, tetrabutylammonium, 1-dodecyl-3-methylimidazolium and N-dodecylimidazolium cations ([TBA]2SW2, [DMIM]2SW2 and [HDIM]2SW2 for short, respectively) have been constructed and utilized for the epoxidation of cis-cyclooctene. Experimental results indicated that the cations of the ionic liquid had a significant effect on the catalytic performance. The catalysts [DMIM]2SW2 and [HDIM]2SW2 can be easily separated and recycled in ethyl acetate media, in comparison with [TBA]2SW2 catalyst at a molar ratio of the cis-cyclooctene to H2O2 = 1:1. It is interesting to note that the catalytic activity increased in the second run with [DMIM]2SW2 or [HDIM]2SW2 as catalyt, which probably resulted from catalyst activation with H2O2 in the first run. Finally,[HDIM]2SW2 has been chosen as a typical catalyst to investigate the effect of reaction solvent, catalyst separation and recyclability in ethyl acetate.