أقرأ أيضاً
التاريخ: 11-9-2019
821
التاريخ: 11-9-2020
1103
التاريخ: 21-11-2019
1377
التاريخ: 30-6-2018
1904
|
Two simple mechanisms can be written for the reaction of chloromethane with hydroxide ion in aqueous solution that differ in the timing of bond breaking relative to bond making. In the first mechanism, A, the overall reaction is the result of two steps, the first of which involves a slow dissociation of chloromethane to solvated methyl carbocation 4 and solvated chloride ion. The second step involves a fast reaction between the carbocation and hydroxide ion (or water) to yield methanol.
Mechanism A:
or
In the second mechanism, B, the reaction proceeds in a single step. Attack of hydroxide ion at carbon occurs simultaneously with the loss of chloride ion; that is, the carbon-oxygen bond is formed as the carbon-chlorine bond is broken:
Mechanism B:
Both of these mechanisms are important in the displacement reactions of alkyl compounds, although chloromethane appears to react only by Mechanism BB. Now we will discuss the criteria for distinguishing between the concerted and stepwise mechanisms.
|
|
تفوقت في الاختبار على الجميع.. فاكهة "خارقة" في عالم التغذية
|
|
|
|
|
أمين عام أوبك: النفط الخام والغاز الطبيعي "هبة من الله"
|
|
|
|
|
المجمع العلمي ينظّم ندوة حوارية حول مفهوم العولمة الرقمية في بابل
|
|
|