A DFT Study on the Stability and Aromaticity of Heterobenzenes Containing Group 15 Elements

The stability and aromaticity of 36 heterobenzenes containing group 15 elements were evaluated at the B3LYP/6-311+G(d,p) level of theory. Stability evaluation was performed based on the enthalpies of formation calculated from imaginary reactions and on the absolute hardness reactivity descriptor. The aromaticity was investigated by means of geometric (Bird, Harmonic Oscillator Model of Aromaticity (HOMA) indices), energetic (aromatic stabilization energy), and magnetic criteria (nucleus-independent chemical shifts [NICS] index). Also, within the conceptual density functional theory (DFT) theory, reactivity-based descriptors (highest occupied molecular orbital and lowest unoccupied molecular orbital [HOMO—LUMO] energy gap, absolute hardness, electrophilicity) were computed. The results led to the conclusion that all heterobenzenes exhibit aromatic character, which generally decreases from N to As containing compounds and from one to six substituted CH groups.