Double bond isomerization of butene catalyzed by 1-ethyl-3-methyl-imidazolium chloride: Concerted or stepwise mechanism?
✍ Scribed by Liangxu Xie; Dongju Zhang; Xuejiao Liu; Xi Zhang; Panpan Duan
- Publisher
- Elsevier
- Year
- 2011
- Tongue
- English
- Weight
- 543 KB
- Volume
- 963
- Category
- Article
- ISSN
- 2210-271X
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✦ Synopsis
The double bond isomerization of butene catalyzed by 1-ethyl-3-methyl-imidazolium chloride ionic liquid has been examined by performing density functional theory calculations at the B3LYP/6-31G (d, p) level. The stepwise H-migration pathway is compared with the concerted H-migration pathway proposed in the early literature. The calculated elementary step barriers in the stepwise mechanism are 35.1 and 24.7 kcal/mol, in contrast to 55.1 kcal/mol found in the concerted mechanism. This fact implies that the isomerization reaction may proceed according to the stepwise rather than concerted mechanism. The present results provide a general mechanism picture for the double bond isomerization of olefin in imidazolium-based ionic liquids.