DFT and Docking Calculations of the Structural, Electronic, Biological and Conductivity Properties of the Synthetic Complex [Cu(hfac)₂(L)₂][PF₆]₂

Abstract

In the present research, we report a theoretical study of Cu II complex based on TTF ligand [Cu(hfac)2(L)2][PF6]2 (in neutral and oxidized states +1 and +2, of biological interest and various applications in magnetic conducting materials. It is an organic/inorganic hybrid material involving a coordination between a paramagnetic transition metal and a nitrogenous aromatic TTF linked through a covalent transition conjugate bridge. The optimized structures of neutral and oxidized metal transition complexes obtained using the Density Functional Theory (DFT) method are consistent with the experimental results. Several properties including geometrical parameters, Hirshfeld atomic charges, energies of Frontier Molecular Orbitals (FMOs), and energy gap (ΔEgap) between the Highest Occupied Molecular Orbital (HOMO), and the Lowest Unoccupied Molecular Orbital (LUMO) are calculated for optimized complexes. The results reveal that oxidation leads to more stable aromatic systems and reduces the energy gap. The analysis of the charges as well as the distribution of the spin density in the frontier orbitals shows that the oxidation takes place at the ligand level. More precisely the ylidene C3=C4 bond is the most sensitive molecular part to oxidation. A significant degeneracy of molecular orbitals is also observed. No metallic contribution in the HOMO of Cu complex reveals a strong electronic localization at the end of the chain, and, at the same time a delocalization along the chain, this is also in favor of a good conductivity and excellent catalytic activity of this compounds.