Computational insights into the role of the frontiers orbital in the chemistry of tridentate ligands

Abstract

The FERMO concept emerges as a powerful and innovative implement to investigate the role of molecular orbitals applied in the description of breakage and formation of chemical bonds. In this work, Hartree-Fock (HF) and Density Functional Theory (DFT) calculations were carried out for a series of four tridentate ligands and their behavior was analyzed using molecular orbital (MO) energies. It was observed that HOMO energies are inadequate to describe the Pearson´s Hard and Solf acid-base (HSAB) pricinple behavior of these compounds. By using the frontier effective-for-reaction molecular orbital (FERMO) concept, the reactions that are driven by HOMO, and those that are not, can be better explained, independent of the calculation method used, since both HF and Kohn-Sham methodologies lead to the same FERMO.