Postformation Modification of SAMs: using click chemistry to functionalize organic surfaces

We have investigated a recently established strategy of modifying organic surfaces exposed by thiolate SAMs (self-assembled monolayers) deposited on Au substrates by employing so-called click chemistry. This term is used to denote a modified Huisgen 1,3-dipolar cycloaddition. We demonstrate the potential of this method by coupling ferrocene and azido acetic acid to alkyne/azide-terminated SAMs. After the surface reaction, the modified organic monolayers were analyzed using infrared spectroscopy (IR), X-ray photoelectron spectroscopy (XPS), and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. Under the conditions used in this study, only for the azide-terminated SAMs could successful grafting of the ferrocene be achieved whereas for the alkyne-terminated SAMs the spectroscopic studies reveal a rather low yield of the coupling reaction.