A density functional theory study of the adsorption of sulfur, mercapto,
and methylthiolate on Au(111)

A density functional theory study of the adsorption of sulfur, mercapto, and methylthiolate on Au(111)
======================================================================================================

by J. Gottschalck and B. Hammer.

J. Chem. Phys. **116**, 784 (2002).

Abstract
--------

We have studied the adsorption of sulfur (S=), mercapto (HS-) and
methylthiolate (CH3S-) on Au(111). The three adsorbates are found to
form strong bonds to the gold surface through the S-end. While the
sulfur atom adsorbs in the high coordinated fcc site, the mercapto and
methylthiolate molecules adsorb in bridge or bridge-like sites. The
bending of the sulfur-hydrogen and sulfur-methyl bonds away from the
surface normal plays a key role in this sites preference. We show that
the back bonded sulfur species prefer the bridge sites because of lower
steric repulsion at these sites between the gold surface and the
hydrogen and methyl groups respectively.