Cyclopentyl, cyclohexyl, and cycloheptyl cations: computational studies of the structures, stability, ¹³C NMR chemical shifts, and possible rearrangement pathways

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• 作者：G. K. Surya Prakash ; Golam Rasul
• 关键词：Secondary carbocations ; Equilibrating cations ; Ab initio methods ; MP2/cc ; pVTZ level ; 13C NMR chemical shifts ; GIAO ; CCSD (T)
• 刊名：Structural Chemistry
• 出版年：2017
• 出版时间：April 2017
• 年：2017
• 卷：28
• 期：2
• 页码：317-326
• 全文大小：
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Computer Applications in Chemistry; Physical Chemistry; Theoretical and Computational Chemistry;
• 出版者：Springer US
• ISSN：1572-9001
• 卷排序：28

文摘

Various structures of the cyclopentyl cation were computed at the MP2/cc-pVTZ and CCSD (T)/cc-pVTZ levels. Energetically, the classical cyclopentyl cation 1 and the 1,2-hydrogen-bridged structure 3 were found to be almost identical. The structures and energies of the cyclohexyl and cycloheptyl cations were also calculated at the MP2/cc-pVTZ level. The σ-delocalized nonclassical ion 16 was found to be the lowest energy structure for the cycloheptyl cation. The 13C NMR chemical shifts of the ions were also computed and compared with the experimental results.