Reversible exchange of self-assembled monolayers of semifluorinated n-alkanethiols and n-alkanethiols on Au/mica surfaces

Scanning tunnelling Microscopy (STM) and photoelastic modulation infrared reflection absorption spectroscopy (PM-IRRAS) have been used to investigate the exchange of self-assembled rnonolayers (SAMs) of n-octanethiolate by semifluorinated n-octanethiolate from ethanolic solution at 340 K. The process occurs via displacement of the thiols from domain boundaries. By contrast, the reverse exchange process occurs more homogeneously via the formation of mixed thiolate domains. The ability of semifluorinated octanethiolate to adopt a range of adsorption sites with approximately similar adsorption energies may lead to this contrasting behavior.