The pyramidal molecule C7N6H6 and its nine symmetric tri-substituted derivatives C7N6–H3R3 (R=OH, F, CN, N3, NH2, NO2, N=NH, N2H3, and C≡CH) were investigated computationally using the GAUSSIAN 09 program package. Natural bond orbital and atoms in molecules analyses, as well as valence bond theory were applied to investigate the bonding properties. In comparison to their well known analogues C6N7–R3, i.e. generic heptazines, it is found that these 10 molecules are all reactive. Further studies on the topological structures and ionization energy values indicate that the reactive site of the molecules is located at the carbon atom of the core frame. Even though C7N6–H3R3 are neutral molecules, the structures and properties of some are consistent with those of a carbanion, and indeed, they act like carbanions, or so-called carbanionoids. These carbanionoids may have an extensive impact in organic chemistry and organometallic chemistry.
Experimental study of flexural-torsional deformations and stability of curved elements of steel arches with l-shaped cross-section