Stereochemical Dependence of (3)J(CH) Coupling Constants in 2-Substituted 4-t-Butyl-cyclohexanone and Their Alcohol Derivatives

Author(s)

Favaro, Denize C. ^[1] ; Ducati, Lucas C. ^[1] ; dos Santos, Francisco P. ^[1] ; Contreras, Ruben H. ^{[2, 3]} ; Tormena, Claudio F. ^[1]

Affiliation

^[1] Univ Estadual Campinas, Inst Chem, BR-13084971 Campinas, SP - Brazil

^[2] Univ Buenos Aires, Dept Phys, FCEyN, Buenos Aires, DF - Argentina

^[3] Consejo Nacl Invest Cient & Tecn, IFIBA, RA-1033 Buenos Aires, DF - Argentina

• Document type: Journal article
• Source: Journal of Physical Chemistry A; v. 115, n. 50, p. 14539-14545, DEC 22 2011.
• Web of Science Citations: 7

Abstract

Theoretical and experimental studies on (3)J(C2H6eq) NMR spin-spin 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 (3)J(C2H6eq) couplings versus the C-2-C-1-C-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 (3)J(C2H6eq) couplings is discussed and rationalized in terms of different Fermi contact transmission pathways. (AU)

• FAPESP's process: 10/10993-9 - Transmission mechanism through space scalar coupling constants in NMR
• Grantee: Claudio Francisco Tormena
• Support Opportunities: Regular Research Grants