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Federico J Williams - One of the best experts on this subject based on the ideXlab platform.

  • Molecular and Electronic Structure of Self-Assembled Monolayers Containing Ruthenium(II) Complexes on Gold Surfaces
    Journal of Physical Chemistry C, 2014
    Co-Authors: Ezequiel De La Llave, Santiago E. Herrera, Federico J Williams
    Abstract:

    Ru(II) bipyridyl complexes were covalently bonded to self-assembled monolayers (SAM) on Au surfaces. Their Molecular and electronic structure was studied by means of polarization modulation infrared reflection absorption spectroscopy (PM-IRRAS), photoelectron spectroscopies, scanning tunneling microscopy (STM) and density functional theory (DFT) calculations. We found that attaching the Ru complex to the SAM does not cause great modifications to its Molecular structure, which retains the alkyl chain 30 deg tilted with respect to the surface normal. Furthermore, the Ru center is located 20 A away from the metal surface, i.e., at a sufficient distance to prevent direct electronic interaction with the substrate. Indeed the electronic structure of the Ru complex is similar to that of the free molecule with a HOMO Molecular Orbital mainly based on the Ru center located 2.1 eV below the Fermi edge and the LUMO Molecular Orbital based on the bipyridine groups located 1 eV above the Fermi level.

Christophe Len - One of the best experts on this subject based on the ideXlab platform.

  • Furfural Analogs as Sustainable Corrosion Inhibitors-Predictive Efficiency Using DFT and Monte Carlo Simulations on the Cu(111), Fe(110), Al(111) and Sn(111) Surfaces in Acid Media
    Sustainability, 2020
    Co-Authors: Hassan Bourzi, Rachid Oukhrib, Brahim El Ibrahimi, Hicham Abou Oualid, Youness Abdellaoui, Bouchra Balkard, Souad El Issami, Mustapha Hilali, Lahcen Bazzi, Christophe Len
    Abstract:

    Nowadays, theoretical calculation tools have become powerful in predicting the behavior of corrosion inhibitors on the surface of metals and, therefore, avoiding energy consumption and the cost of experimental tests. This work aims to predict the inhibitory power of some furan derivatives on Cu (111), Fe (110), Al (111) and Sn (111) surfaces in acidic media. For this purpose, three furan derivatives-furan-2-carbaldehyde (FF1), 5-(hydroxymethyl)furfural (FF2) and 5-(hydroxymethyl)furoic acid (FF3)-have been selected to compare their intrinsic properties against corrosion as well as their behavior on iron (Fe), copper (Cu), aluminum (Al) and tin (Sn) surfaces in acid medium. Typically, the anti-corrosive properties of FF1, FF2 and FF3 were studied by using quantum chemical calculations and Monte Carlo simulations. Density Functional Theory (DFT), lowest unoccupied (E LUMO) and highest occupied (E HOMO) Molecular Orbital energies, energy gap (∆E), chemical hardness (η), softness (σ), electronegativity (χ), electrophilicity (ω) and nucleophilicity (ε) have been calculated and discussed. Theoretical vibrational spectra were also calculated to exhibit the functional groups in the selected chemicals. On the other hand, the adsorption behaviors of FF1, FF2 and FF3 were studied on the Fe(110), Cu(111), Al(111) and Sn(111) surfaces. As a result, the adsorption energies of all molecules are ordered as Fe(110) < Cu(111) < Al(111) < Sn(111) and FF3 seems to be more effective as a corrosion inhibitor due to the existence of both carboxylic acid and hydroxyl groups, which consist of favorable sites of adsorption into the metal surface.

Ezequiel De La Llave - One of the best experts on this subject based on the ideXlab platform.

  • Molecular and Electronic Structure of Self-Assembled Monolayers Containing Ruthenium(II) Complexes on Gold Surfaces
    Journal of Physical Chemistry C, 2014
    Co-Authors: Ezequiel De La Llave, Santiago E. Herrera, Federico J Williams
    Abstract:

    Ru(II) bipyridyl complexes were covalently bonded to self-assembled monolayers (SAM) on Au surfaces. Their Molecular and electronic structure was studied by means of polarization modulation infrared reflection absorption spectroscopy (PM-IRRAS), photoelectron spectroscopies, scanning tunneling microscopy (STM) and density functional theory (DFT) calculations. We found that attaching the Ru complex to the SAM does not cause great modifications to its Molecular structure, which retains the alkyl chain 30 deg tilted with respect to the surface normal. Furthermore, the Ru center is located 20 A away from the metal surface, i.e., at a sufficient distance to prevent direct electronic interaction with the substrate. Indeed the electronic structure of the Ru complex is similar to that of the free molecule with a HOMO Molecular Orbital mainly based on the Ru center located 2.1 eV below the Fermi edge and the LUMO Molecular Orbital based on the bipyridine groups located 1 eV above the Fermi level.

Hassan Bourzi - One of the best experts on this subject based on the ideXlab platform.

  • Furfural Analogs as Sustainable Corrosion Inhibitors-Predictive Efficiency Using DFT and Monte Carlo Simulations on the Cu(111), Fe(110), Al(111) and Sn(111) Surfaces in Acid Media
    Sustainability, 2020
    Co-Authors: Hassan Bourzi, Rachid Oukhrib, Brahim El Ibrahimi, Hicham Abou Oualid, Youness Abdellaoui, Bouchra Balkard, Souad El Issami, Mustapha Hilali, Lahcen Bazzi, Christophe Len
    Abstract:

    Nowadays, theoretical calculation tools have become powerful in predicting the behavior of corrosion inhibitors on the surface of metals and, therefore, avoiding energy consumption and the cost of experimental tests. This work aims to predict the inhibitory power of some furan derivatives on Cu (111), Fe (110), Al (111) and Sn (111) surfaces in acidic media. For this purpose, three furan derivatives-furan-2-carbaldehyde (FF1), 5-(hydroxymethyl)furfural (FF2) and 5-(hydroxymethyl)furoic acid (FF3)-have been selected to compare their intrinsic properties against corrosion as well as their behavior on iron (Fe), copper (Cu), aluminum (Al) and tin (Sn) surfaces in acid medium. Typically, the anti-corrosive properties of FF1, FF2 and FF3 were studied by using quantum chemical calculations and Monte Carlo simulations. Density Functional Theory (DFT), lowest unoccupied (E LUMO) and highest occupied (E HOMO) Molecular Orbital energies, energy gap (∆E), chemical hardness (η), softness (σ), electronegativity (χ), electrophilicity (ω) and nucleophilicity (ε) have been calculated and discussed. Theoretical vibrational spectra were also calculated to exhibit the functional groups in the selected chemicals. On the other hand, the adsorption behaviors of FF1, FF2 and FF3 were studied on the Fe(110), Cu(111), Al(111) and Sn(111) surfaces. As a result, the adsorption energies of all molecules are ordered as Fe(110) < Cu(111) < Al(111) < Sn(111) and FF3 seems to be more effective as a corrosion inhibitor due to the existence of both carboxylic acid and hydroxyl groups, which consist of favorable sites of adsorption into the metal surface.

Santiago E. Herrera - One of the best experts on this subject based on the ideXlab platform.

  • Molecular and Electronic Structure of Self-Assembled Monolayers Containing Ruthenium(II) Complexes on Gold Surfaces
    Journal of Physical Chemistry C, 2014
    Co-Authors: Ezequiel De La Llave, Santiago E. Herrera, Federico J Williams
    Abstract:

    Ru(II) bipyridyl complexes were covalently bonded to self-assembled monolayers (SAM) on Au surfaces. Their Molecular and electronic structure was studied by means of polarization modulation infrared reflection absorption spectroscopy (PM-IRRAS), photoelectron spectroscopies, scanning tunneling microscopy (STM) and density functional theory (DFT) calculations. We found that attaching the Ru complex to the SAM does not cause great modifications to its Molecular structure, which retains the alkyl chain 30 deg tilted with respect to the surface normal. Furthermore, the Ru center is located 20 A away from the metal surface, i.e., at a sufficient distance to prevent direct electronic interaction with the substrate. Indeed the electronic structure of the Ru complex is similar to that of the free molecule with a HOMO Molecular Orbital mainly based on the Ru center located 2.1 eV below the Fermi edge and the LUMO Molecular Orbital based on the bipyridine groups located 1 eV above the Fermi level.