灵鹊做题网卤代烃和硝酸银的醇溶液反应为什么不用水溶液
来源：学生作业帮 编辑：灵鹊做题网作业帮 分类：综合作业 时间：2024/05/04 09:36:25
卤代烃和硝酸银的醇溶液反应为什么不用水溶液
同题
匿名干嘛啊,我还想问你呢.都别匿名.
再说,这反应是消除吗,没有碱.不应该是取代吗
同题
匿名干嘛啊,我还想问你呢.都别匿名.
再说,这反应是消除吗,没有碱.不应该是取代吗
看你的卤代烃溶不溶于水吧,不溶的话就用醇溶液.
Heterolytic cleavage of the carbon-halogen bond of alkyl halides may be facilitated by the presence of certain metal cations. In the extreme, carbocations may be generated as shown in the following equation, where R is alkyl or hydrogen, and M = Al (n=3) or Fe (n=3) or Sn (n=4) or Zn (n=2).
R3C-X + MXn (reactivity = Al > Fe > Sn > Zn) ——> R3C(+) + MXn-X(–)
Although this technique is useful for generating carbocation intermediates in hydrocarbon solvents, the metal halide reactants are deactivated in protic solvents such as water and alcohol, rendering these reactants relatively useless for inducing SN1 reactions. There is, however, a related halophilic reactant that accomplishes this. This compound is silver nitrate, and in aqueous or alcoholic solution it promotes ionization of the alkyl halide and the formation of SN1 products.
!Polar solvents which can stabilise carbocations which can favour the SN1 reaction (e.g. H2O, ROH)
E1通常需要碱性环境.
Heterolytic cleavage of the carbon-halogen bond of alkyl halides may be facilitated by the presence of certain metal cations. In the extreme, carbocations may be generated as shown in the following equation, where R is alkyl or hydrogen, and M = Al (n=3) or Fe (n=3) or Sn (n=4) or Zn (n=2).
R3C-X + MXn (reactivity = Al > Fe > Sn > Zn) ——> R3C(+) + MXn-X(–)
Although this technique is useful for generating carbocation intermediates in hydrocarbon solvents, the metal halide reactants are deactivated in protic solvents such as water and alcohol, rendering these reactants relatively useless for inducing SN1 reactions. There is, however, a related halophilic reactant that accomplishes this. This compound is silver nitrate, and in aqueous or alcoholic solution it promotes ionization of the alkyl halide and the formation of SN1 products.
!Polar solvents which can stabilise carbocations which can favour the SN1 reaction (e.g. H2O, ROH)
E1通常需要碱性环境.