XAS and XPS characterization of a surface-attached rotaxane

X-ray absorption spectroscopy (XAS) and X-ray photoemission spectroscopy (XPS) were utilized to characterize a surface-attached rotaxane on Au(111). Monolayers were prepared from an anthracene-stoppered thiol thread, a pseudorotaxane obtained by mixing the thiol with dibenzo-24-crown-8 and a disulfide-containing [3]rotaxane. XAS and XPS showed clear distinctions between the monolayers, allowing identification of spectral contributions from the separate components of the surface-attached rotaxane. Spectroscopic data clearly showed that only the [3]rotaxane gave the desired gold-bound interlocking molecule.