D. Forsyth, J. Hanley
Dec 1, 1987
Citations
0
Influential Citations
19
Citations
Journal
Journal of the American Chemical Society
Abstract
A large conformational equilibrium isotope effect (CEIE) in N-methylpiperidine and also a substantial difference in the intrinsic isotope effect on the /sup 15/N chemical shift due to axial and equatorial deuterium at neighboring carbons are reported. The isotope shifts at /sup 15/N are intrinsic and not the result of an equilibrium isotope effect such as the perturbation of an equilibrium between axial and equatorial N-methyl conformers. The CEIE of 61 cal/mol per deuterium in N-methylpiperidine can be entirely accounted for, within the error limits, by zero-point energy contributions associated with the C-H stretching frequencies.