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Grignard试剂(乙基溴化镁,苯基溴化鎂)与二氯化钴反应所产生的钴催化剂不能直接与溴乙烷反应,但若有过剩的Grignard试剂存在时,立即引起反应,产生乙烷和乙烯。若在反应体系中加入苯乙烯,气体的形成受到抑制,从反应混合物中可以测定苯乙烯的消耗,并分离出聚苯乙烯,若在反应体系中加入異丙苯,可以分离出脱氢介偶合产物,2,3-二甲基-2,3-二苯基丁烷。 Grignard(试剂与二氯化钴反应所产生的钴催化剂,在氮气下保存一星期后,仍然具有活性,而能连续地引起Grignard试剂与溴乙烷的反应,生成乙烷及乙烯,钴催化剂因此可能是一种活性金属钴。建议Grignard试剂与卤代烷在少量二氯化钴催化下的反应包括如下的重要步骤: RMgx+R’×+Co→R·+R’+Co+Mgx_2反应可能是在活性钴的表面上通过某种結合物的形成而进行的。
The cobalt catalyst produced by the reaction of Grignard reagent (ethylmagnesium bromide, phenylmagnesium bromide) with cobalt dichloride can not react directly with ethylbromoethane, but in the presence of excess Grignard reagent, a reaction is initiated immediately to produce B Alkane and ethylene. If styrene is added to the reaction system, gas formation is inhibited, styrene consumption can be measured from the reaction mixture, and polystyrene is separated. If cumene is added to the reaction system, a dehydrogenation mediated coupling Product, 2,3-dimethyl-2,3-diphenylbutane. Grignard (The cobalt catalyst produced by the reaction of the reagent with cobalt dichloride remains active for one week after it has been stored under nitrogen and can continuously cause the reaction of Grignard reagent with ethyl bromide to form ethane and ethylene. The cobalt catalyst thus It may be an active metal cobalt.It is suggested that the reaction of Grignard reagent with alkyl halides catalyzed by a small amount of cobalt dichloride includes the following important steps: RMgx + R ’× + Co → R · + R’ + Co + Mgx_2 The reaction may be at The surface of the active cobalt is made by the formation of a certain binder.