Rational Design of Stable Dianions by Functionalizing Polycyclic Aromatic Hydrocarbons

Using density functional theory, we have carried out a systematic study of the stability and electronic properties of neutral and multiply charged molecules B n C 10‐ n X 8 ( n =0, 1, 2; X=H, F, CN). Our main objective is to explore if the replacements of core C atoms and/or H atoms in naphthalene (C 10 H 8 ) can enhance the stability of their dianions. Indeed, we find that the dianions of B n C 10‐ n (CN) 8 are more stable than their monoanions with energies of 0.61 eV, 0.57 eV, and 1.97 eV for n= 0, 1, 2, respectively. In addition, polycyclic aromatic hydrocarbons become stable as dianions only when H atoms are substituted by more electronegative species. Thus, a rational design approach by tailoring composition and ligands can lead to a new class of organic molecules that are capable of carrying multiple charges.