From Halogen to Superhalogen Behavior of Organic Molecules Created by Functionalizing Benzene.

Benzene, the classic organic molecule obeying Hückel's rule of aromaticity, has negative electron affinity (EA), namely -1.15 eV. By using density functional theory with hybrid functional for exchange and correlation potential, we show that a series of organic molecules created by changing either the benzene core or the ligands, or both, result in species with EAs that range from 2.15 to 5.37 eV. This shows that ligand substitution is more effective than aromaticity in increasing the EA of organic molecules. The ability to create highly electronegative organic molecules by functionalizing benzene may provide new opportunities for synthesizing organic oxidizing agents with potential new applications.