Microwave spectrum and non-planarity of 2-aminopyrimidine

Abstract

The microwave spectra of the ground and first three excited states of the inversion vibration of 2-aminopyrimidine-NH₂ and for the ground and first excited inversion state of 2-aminopyrimidine-ND₂ have been assigned. Vibration rotation interactions prevent an accurate determination of the amine group geometry but there is considerable evidence to indicate a greater tendency towards molecular planarity in 2-aminopyrimidine than in a number of other amine molecules. SCF computations using STO/3G orbitals support this suggestion.