Adsorption state of dimethyl disulfide on Au(111): Evidence for adsorption as thiolate at the bridge site

Abstract

We studied the adsorption state of dimethyl disulfide and methylthiolate on the Au(111) surface by means of the density functional theory (DFT) within a generalized gradient approximation and experimental high-resolution electron energy loss spectroscopy (HREELS) techniques. It turns out that the methylthiolate adsorption is more stable than the dimethyl disulfide adsorption and that the most stable adsorption site for the methylthiolate is the bridge site slightly off-centered towards the fcc-hollow site with its S–C bond tilted from the surface normal by 53°. HREELS results are in excellent agreement with the DFT results, providing very strong support to the depicted adsorption scenario.

Thiolate adsorption on Au(${\bm {hkl}}$hkl) and equilibrium shape of large thiolate-covered gold nanoparticles

“…In particular, for Au(111) our minimum energy adsorption geometry is identical to that presented by Hayashi et al 48 and by Maksymovych et al 47 The on top site was found to be the most unfavourable one, followed by the hollow site. In all stepped surfaces, the methyl part is oriented above steps and in all cases in such a way that one of the hydrogen atoms is directed towards the surface, whereas the other two are pointing away from the surface.…”

“…These results agree with the calculations of Molina and Hammer 8 who found −1.13 eV for (b) and +0.40 eV for (d). For (a), Hayashi et al, 48 report a bridge site adsorption with −0.27 eV per CH 3 S using the PBE exchange-correlation functional. Although the adsorption energy is different, there is good agreement for adsorption geometry.…”

First-principles molecular dynamics study of Al/Alq3interfaces

“…Calculations were carried out by using the first-principles molecular dynamics program ''STATE'' (Simulation Tool for Atom TEchnology) which has been applied to organic/ metal interfaces [23][24][25][26]. We employed the local density approximation (LDA) [27,28] and the generalized gradient approximation (GGA) [29] for the exchange-correlation energy functional.…”

Intermolecular effect in molecular electronics

“…We used the Kohn-Sham method in the generalized gradient approximation for the electronic structure calculation, with numerical atomic orbitals (double zeta plus polarization) The initial and relaxed site, the adsorption energy with respect to the fcc-bridge case, the height of the sulfur atom from the gold surface, the average of the three nearest neighbor Au-S distances, and the S-C bond length and angle θ to the surface normal. (81 k-points are used, yielding a converged adsorption energy [20].) as the basis set, by means of the SIESTA program [18].…”