Sixteen valence-electron species containing boron: structural diversity abounds

Abstract

[B, C, F, H₂] and [B, N, O, H₂] have been investigated via high level ab initio calculations. Both cyclic and acyclic connectivities have been examined for the singlet state. Chemical intuition suggests a ketene-like structure for each system, with the general form H₂XBY, where X = C or N and Y = F or O. The calculations yield a variety of possible structures for these species, including both cyclic and the expected acyclic, hydrogen-bonded and fluorine-bridged. Eight minima have been located for [B, C, F, H₂] at both calculational levels. Fifteen minima have been located for [B, N, O, H₂]. Barriers to the rearrangements between isomers in the [B, C, F, H₂] system have also been evaluated. AIM and NBO analyses have been carried out to gain an understanding of the bonding in the various isomeric forms of [B, C, F, H₂] and [B, N, O, H₂].