On the structure and stability of cyclic cyanoborane isomers

Abstract

Cyclic isomers of the cyanoboranes (HCNBH)_n and (BH₂CN)_n up to hexamers have been studied using density functional theory. Their relative stability changes with the size of the ring and the temperature, within the range 200–800 K the pentamer is the most populated species (tetramer and hexamer are likely to appear as traces). NMR parameters and IR frequencies calculated for (BH₂CN)_n oligomers agree well with available experimental data.