Abstract
Results from a new dynamic n.m.r. method, applicable to heavily biased equilibria, and kinetically controlled protonation studies agree when applied to 1,2,2,6-tetramethylpiperidine, giving the free energy difference for
N
-inversion [Δ
G
°(
1E
→
1A
)] as
1
-
9
± 0·2 at 213 K (d.n.m.r.) and 1·95 ± 0·1 kcal mol
-1
at 293 and 373 K (kinetic protonation); the free energy of activation [Δ
G
‡
(
1E
→
1A
)] is 11·0 ± 0·3 kcal mol
-1
at 213 K.