کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5418043 | 1506972 | 2007 | 6 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
The influence of the leaving group X (XÂ =Â F, Cl, Br, I) on the carbenoid nature of the carbenoids X2AlCH2X - A theoretical study
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موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی تئوریک و عملی
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چکیده انگلیسی
The cyclopropanation reaction of ethene with aluminum carbenoid has been studied by means of the B3LYP hybrid density functional method. The reaction goes through two pathways: methylene transfer and carbometalation. In methylene transfer pathway, a quantum-chemical investigation shows that the reactions of the carbenoids X2AlCH2X 1-X, (XÂ =Â F, Cl, Br, I) with ethene 2 to cyclopropane 3Â +Â lX3 profit from a weakening of the C-X bonds by the C-Al bonds in the carbenoids 1-X and in the complex [1-Xâ2]. The C-F bond is more affected than the C-I bond. Since in the transition states 3[1-Xâ2]â¡ AlHal is strongly decomplexed, the cleavage of the C-Hal bond is essential compensated by the formation of the Al-Hal bonds, which leads to almost equal transition state energy for the reactions of 1-X with 2. In contrast with methylene transfer, the cyclopropanation reaction of the carbometalation pathway profit from a weakening of the C-Al bonds by the C-X bonds.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Molecular Structure: THEOCHEM - Volume 807, Issues 1â3, 1 April 2007, Pages 173-178
Journal: Journal of Molecular Structure: THEOCHEM - Volume 807, Issues 1â3, 1 April 2007, Pages 173-178
نویسندگان
Zhao-Hui Li, Zhi-Yuan Geng, Cunyuan Zhao, Yong-Cheng Wang, Le-Yan Liu,