Calculated and experimental equilibrium steric isotope effects for carbon in cis-1-[13C]methyl-4-methylcyclohexane
Abstract
A conformational steric isotope effect for carbon in a methyl group in cis-1,4-dimethylcyclohexane has been measured as +1.24 ± 0.25 J mol–1 in acetone and +1.25 ± 0.20 J mol –1 in benzene (both at 300 K), i.e., inverse, with 12C preferring to be axial, and smaller in magnitude than estimates from force field calculations.