Quantum mechanical calculations on barriers to internal rotation - II. The borazane molecule BH₃-NH₃

Abstract

SCF LCAO MO calculations are reported for the borazane molecule BH3NH3, for different values of the dihedral angle (0°, 20°, 40°, 60°). The lower energy was found equal to -82.59651 a.u. for the staggered form. The theoretical barrier height, 0.00524 a.u.=3.29 kcal/mole, is very close to the one, 0.00577 a.u., computed by Clementi for the ethane molecule. A study of the electronic density maps seems to indicate that some care should be exercised in the use of the population analysis. According to the criterion of Bader and al., the bond density map seems characteristic of ionic binding. © 1968 Springer-Verlag.