Computational study of cis-oleic acid adsorption on Ni(1 1 1) surface

In the present work, the Atom Superposition and Electron Delocalization method has been applied in order to study the adsorption of cis-oleic acid on Ni(1 1 1) surface. This molecule presents two active functional groups, Cdouble bond; length as m-dashC (in the middle) and single bondCOOH (at one end). Therefore, it is important to explore adsorption on the metal surface through the Cdouble bond; length as m-dashC bond in a geometry parallel to the surface and also in a vertical one with single bondCOOH pointing at Ni atoms. Our results indicate that the parallel geometry is more stable than the vertical one and Cdouble bond; length as m-dashC bond adsorption dominates the process. Energetic results show a strong interaction with the metallic surface. Nisingle bondNi, Cdouble bond; length as m-dashC, and Csingle bondC bonds are weakened upon adsorption because of a bonding interaction between carbons and nickel surface. We found that Ni 5dz2 and 5dyz orbitals play an important role in the bonding between C px, pz orbitals and surface, and the same happens with Ni 6px and Ni 6pz. A small Nisingle bondH interaction is also detected.