Appearance of NMR spectra for system undergoing two-site exchange

The free-energy difference between conformers is referred to as the conformational free energy, or sometimes as the A value. For substituted cyclohexanes, we wiU follow the convention of specifying the value of -AG° for the equilibrium written as  

Since AG° will be negative when the equatorial conformation is more stable than the axial, a positive value of -AG° is indicative of this condition. 

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Fig. 3.5. Appearance of NMR spectra for system undergoing two-site exchange (A B).

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