Ab initio post-HF study of electronic charge density distribution of cyclic (B6C)−2: Concrete evidence of a novel bonding pattern

In this account, the bonding pattern of cyclic (B6C)−2 dianion as a planar hypercoordinate carbon compound is considered employing topological charge density analysis developed within framework of Quantum Theory of Atoms in Molecules. The analysis was done on charge densities derived from post-HF methods. The outcomes of the analysis demonstrate that the nature of interactions between boron atoms and central carbon atom is a novel “non-directional shared interaction”. The intrinsic floppiness of charge density distribution in this molecule also is once again confirmed and a new approach is proposed to systematically study the role of nuclear excursions in similar molecules.