Inversion at trivalent nitrogen: application of the MNDO and MINDO/3 semiempirical molecular orbital methods

Abstract

The recently developed MNDO SCF method with full geometry optimization and standard parameterization gives nitrogen inversional barriers in aziridine derivatives which are in close agreement with experimental data (mean deviation 1.7 kcal mol^–1). Results for acyclic amino compounds are less accurate (mean deviation 3.5 kcal mol^–1). The calculated barriers in some primary NH₂X compounds are too high whereas those in acyclic tertiary amines tend to be too low. The older MINDO/3 method gives better results for ammonia and some primary NH₂X molecules, but seriously underestimates inversional potentials in amines and aziridines. Both rotational and nitrogen inversional potential co-ordinates are calculated for hydroxylamines and methyleneamine.