Carbon boronyls: species with higher viable possibility than boron carbonyls at the density functional theory.

Density functional theory investigations indicate that carbon boronyls (CBO)n (n = 3-7) are considerably more stable in thermodynamics than their boron carbonyl isomers (BCO)n and exhibit aromaticity throughout the whole series. The extra stabilities of (CBO)n originate from their frontier pi molecular orbitals delocalized over the Dnh Cn central rings which are absent in (BCO)n. It is expected that experimental characterization of these (CBO)n species may open a new branch of chemistry on carbon boronyls.