DFT Calculations of Mesembryanthemum nodiflorum Compounds as Corrosion Inhibitors of Aluminum

Density functional theory (DFT) calculations have been performed on Mesembrine, Mesembrenone, Mesembrenol and Tortuosamine, using Gaussian 03 (G03) program with complete optimization of geometries. Quantum parameters and thermodynamic Gibbs function have been used to investigate the efficiency of the corrosion inhibition of each compound. Mesembrenone has been found to have very good corrosion inhibition efficiency as compared to the other compounds. Quantum parameters and frontier orbitals together with calculated thermodynamic function △G for adsorption show spontaneous physical adsorption of the Mesembrenone on aluminum.