Force field calculations on aziridine, N-chloro- and N-bromo-aziridine

Abstract

GVFF calculations were carried out for aziridine and its halogen substituted derivatives. To describe the force field for these small ring systems in an adequate manner an extended combination of internal symmetry coordinates must be adopted. The valence force constants of the N-substituent H, Cl, Br show the same decreasing behaviour as in other compounds where nitrogen has a different number of substituents. Data from spectroscopic measurements are discussed on the basis of a population analysis from ab initio calculations for aziridine and N-chloroaziridine.