高聚物负载型双金属催化剂催化氢转移有机卤化物脱卤

 以甲酸钠为氢转移试剂，以聚乙烯基吡咯烷酮负载PdCl2和其它金属盐制成双金属催化剂PVP－PdCl2－MXn，用于催化有机卤化物脱卤．与负载型单金属催化剂PVP－PdCl2相比，PVP－PdCl2－CdCl2和PVP－PdCl2－HgCl2对氯代芳烃脱氯有高得多的催化活性和脱氯选择性，且偶联副产物显著减少；以对氯苯胺为底物时，双金属催化下的反应时间缩短为单金属催化下的1／8，而脱氯产物收率提高25倍；底物为对氯甲苯时，双金属催化下的偶联副产物仅为单金属催化下的1／390．用IR和TEM技术对PVP负载型金属催化剂进行了表征，并讨论了双金属协同脱卤作用．

Synergistic Effect of Polymer-Supported Bimetallic Catalyst for Hydrogen Transfer Dehalogenation of Organic Halides

The catalytic behavior of PVP supported bimetallic catalyst, made of PdCl 2 and other metal salts, for the dehalogenation of organic halides with sodium formate as hydrogen transfer reagent was studied. It was found that the samples PVP PdCl 2 CdCl 2 and PVP PdCl 2 HgCl 2, compared with PVP PdCl 2, exhibited much higher catalytic activity and dechlorination selectivity, and the yields of the coupling by products were obviously decreased. For example, when p chloroaniline was used as substrate, the reaction time was shortened to 1/8, and the yield of dechlorination product was about 25 times as much as the original one, and when p chlorotoluene was used as substrate, the yield of coupling by product catalyzed by bimetallic catalyst was 1/390 of that catalyzed by monometallic catalyst. A preliminary discussion on the possible synergic effect of bimetallic catalyst has also been made.