Structural study of hexanethiolate on Au(1Â 1Â 1) in the 'striped' phase

We have studied the structure of the 'striped' (flat-lying) phase of hexanethiolate on Au(1 1 1) by using X-ray photoelectron spectroscopy, near edge X-ray absorption fine structure and scanned-energy photoelectron diffraction. Combined results of these techniques indicate that gaseous hexanethiol adsorbs as hexanethiolate in the 'striped' phase with the alkyl chain lying down onto the surface and the S head group occupying an atop site. The S-Au distance was determined to be 2.40 ± 0.05 Å. The present experiments clearly exclude both the multiple-site model and the dimer model.