Understanding of the transition metal (TM) to ligand (L) bonding nature is important for characterization of experimental observations. One of the methods to explain the TM to L interactions is the Dewar–Chatt–Duncanson (DCD) model. However, in most applications the validity of the DCD model is based on assumptions in order to explain trends in vibrational spectroscopy or other physical properties of TM complexes. In this paper the computational methodology for treatment of the π-allyl-ruthenacycle complex based on the density functional theory, restricted Hartree–Fock method, natural bond orbital and charge decomposition analysis is reported. It is shown how the DCD model emerges from the presented calculation scheme and how it relates with the physical properties and stability of this complex. It is important to note that in this work the determination of the DCD model operation is based on the defined computational procedure, not postulated beforehand. The calculated geometry parameters, vibrational frequencies and electron density arrangement for the π-allyl-ruthenacycle complex are in good agreement with the experiment and support the DCD model.
Energy decomposition analysis for exciplexes using absolutely localized molecular orbitals