Stereochemical Dependence of 3JCH Coupling Constants in 2-Substituted 4-t-Butyl-cyclohexanone and Their Alcohol Derivatives

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• 作者：Denize C. Favaro ; Lucas C. Ducati ; Francisco P. dos Santos ; Rub茅n H. Contreras ; Cl谩udio F. Tormena
• 刊名：Journal of Physical Chemistry A
• 出版年：2011
• 出版时间：December 22, 2011
• 年：2011
• 卷：115
• 期：50
• 页码：14539-14545
• 全文大小：871K
• 年卷期：v.115,no.50(December 22, 2011)
• ISSN：1520-5215

文摘

Theoretical and experimental studies on ³J_C2H6eq NMR spin鈥搒pin coupling constants in both the 2-X-4-t-butyl-cyclohexanone (X = H, CH₃, F, Cl, and Br) and in their alcohol derivatives series are reported. Results thus found are rationalized in terms of the transmission of the Fermi contact contribution to such couplings. To this end, dependencies of ³J_C2H6eq couplings versus the C₂鈥揅₁鈥揅₆ angle are compared in both series for equatorial and axial X orientations. The main trend is described in terms of the rear lobes interaction. Besides, for X = halogen atom in equatorial orientation a rather strong interaction between oxygen and halogen lone pairs is observed, and its influence on ³J_C2H6eq couplings is discussed and rationalized in terms of different Fermi contact transmission pathways.