Gauging the Aromatic, Antiaromatic, and Nonaromatic Character of the Dications and Dianions Derived from Fused Carbocyclic and Heterocyclic Compounds

Abstract

Dications and dianions derived from fused PAHs and hetero-PAHs were investigated by means of DFT calculations. The electronic, energetic, and structural features of the singlet and triplet electronic states of these doubly charged species were computationally determined and compared with those of the corresponding neutral parent aromatic and heteroaromatic compounds. The aromatic, nonaromatic or antiaromatic character of the studied diions was evaluated via magnetic criteria, namely NICS and 1HNMR chemical shifts, and by the HOMA structural index. Linear correlations were revealed between the computed HOMO-LUMO gaps and the magnetic parameters which could serve as a guiding tool in the modulation of molecular properties, and for designing new materials derived from this type of compounds.