Relating total 𝜋-electron energy of benzenoid hydrocarbons with HOMO and LOMO energies

Abstract

Within the Huckel molecular orbital model, the total π-electron energy, Eπ, the highest occupied molecular orbital (HOMO) energy, EHOMO, and the lowest occupied molecular orbital (LOMO) energy, ELOMO, can be expressed in terms of eigenvalues of the adjacency matrix of the underlying molecular graph. In this paper, relations between Eπ, EHOMO, and ELOMO are examined. Approximate expressions are established, relating Eπ with EHOMO and ELOMO in the case of benzenoid hydrocarbons.