Molecular Self-Assembly on Ultrathin Metallic Surfaces:  Alkanethiolate Monolayers on Ag(1 × 1)−Au(111)

Fonticelli, Mariano H.; Azzaroni, Omar; Benítez, G.; Martins, M.E.; Carro, Pilar; Salvarezza, Roberto Carlos

doi:10.1021/jp0359384

Cited by 21 publications

(33 citation statements)

References 60 publications

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“…This was done by integrating the main cathodic peak in the current−potential curves obtained in 0.1 M HClO 4 aqueous solutions between 0.0 V versus a reversible hydrogen electrode (RHE) and the so-called Burshtein minimum. 12 The roughness factor average was 1.18 ± 0.03.…”

Section: ■ Introductionmentioning

confidence: 93%

Surface Chemistry of Thiomalic Acid Adsorption on Planar Gold and Gold Nanoparticles

et al. 2014

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The self-assembly of thiomalic acid (TMA) on Au(111) and on preformed Au nanoparticles (AuNPs) protected by weak ligands has been studied by X-ray photoelectron spectroscopy (XPS) and electrochemical techniques. Results show that TMA is adsorbed on the Au(111) surface as thiolate species with a small amount of atomic sulfur (∼10%) and a surface coverage lower than that found for alkanethiols due to steric factors. The amount of atomic sulfur markedly increases when the TMA is adsorbed on AuNPs by the ligand exchange method. We propose that the atomic sulfur is produced as a consequence of C-S bond cleavage, a process that is more favorable at defective sites of the AuNPs surface. The bond scission is also assisted by the presence of the electron-withdrawing carboxy moiety in the α-position relative to the C-S bond. Moreover, the high local concentration of positively charged species increases the stability of the negatively charged leaving group, leading to a higher amount of coadsorbed atomic sulfur. Our results demonstrate that the terminal functionalities of thiols are conditioning factors in the final structure and composition of the adlayers.

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Section: ■ Introductionmentioning

confidence: 93%

Surface Chemistry of Thiomalic Acid Adsorption on Planar Gold and Gold Nanoparticles

et al. 2014

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“…Structural order in SAMs is a key point to improve their blocking ability for electron tranfer. [62,71] Also, the introduction of methylene units leads to benzyl mercaptan to increase their coverage to 0.33 in relation to 0.25 observed for benzenethiol, thus resulting in better blocking ability [72]. Therefore, one can expect that E p should depend not only on E b * but also on θ through the SAM order/disorder.…”

Section: Accepted Manuscriptmentioning

confidence: 99%

The electrochemical stability of thiols on gold surfaces

Salvarezza

Carro

2018

Journal of Electroanalytical Chemistry

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In this paper we present a comparative analysis of the electrochemical stability of alkanethiols, aromatic and heterocyclic thiols on the Au(111) and Au(100) faces in relation to the theoretical energetic data. The peak potential and surface coverage are used as the key parameters to estimate the electrochemical stability while work function changes, adsorption energies and surface free energies calculated from periodic DFT, including van der Waals interactions, are used for the theoretical estimation. We find that the peak potentials do not correlate with work function changes and adsorption energies in particular for aromatic and heterocyclic thiols. In contrast, the reductive desorption potentials for the different thiols show a good correlation with the surface free energy of the SAMs estimated by density functional theory calculations. Surface coverage is a key factor that controls reductive desorption through van der Waals interactions.

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“…• structure with a nearest neighbor distance of 4.6-4.8Å [38,39], whereas short chain alkanethiolates keep the commensurate structure [17]. Recently a new model has been proposed for the (…”

Section: Structuresmentioning

confidence: 99%

Dipole Formation at Interfaces of Alkanethiolate Self-assembled Monolayers and Ag(111)

2007

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The formation of interface dipoles in self-assembled monolayers (SAMs) of -CH3 and -CF3 terminated short-chain alkanethiolates on Ag(111) is studied by means of density functional theory calculations. The interface dipoles are characterized by monitoring the change in the surface work function upon adsorption of the SAM. We compare results obtained for SAMs in structures with a different packing density of molecules, i.e. (• , and p(2×2). The work function of alkanethiolate SAMs on silver depends weakly on the packing density; that of fluorinated alkanethiolates shows a stronger dependance. The results are analyzed in terms of two nearly independent contributions to the interface dipole. These originate respectively from the molecular dipoles and from a charge transfer between the metal surface and the molecules. The charge transfer is determined by the silver-sulfur bond and it is independent of the electronegativity of the molecules.

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Molecular Self-Assembly on Ultrathin Metallic Surfaces: Alkanethiolate Monolayers on Ag(1 × 1)−Au(111)

Cited by 21 publications

References 60 publications

Surface Chemistry of Thiomalic Acid Adsorption on Planar Gold and Gold Nanoparticles

Surface Chemistry of Thiomalic Acid Adsorption on Planar Gold and Gold Nanoparticles

The electrochemical stability of thiols on gold surfaces

Dipole Formation at Interfaces of Alkanethiolate Self-assembled Monolayers and Ag(111)

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