Evidence of click and coordination reactions on a self-assembled monolayer by synchrotron radiation based XPS and NEXAFS

• Published in: Journal of electron spectroscopy and related phenomena 2012-04, Vol.185 (3-4), p.85-89
• Main Authors: Darlatt, Erik, Traulsen, Christoph H.-H., Poppenberg, Johannes, Richter, Sebastian, Kühn, Julius, Schalley, Christoph A., Unger, Wolfgang E.S.
• Format: Article
• Language: English
• Subjects: HAXPES; NEXAFS spectroscopy; Self-assembled monolayer; Surface click chemistry; Synchrotron radiation XPS; XANES
• ISSN: 0368-2048; 1873-2526
• DOI: 10.1016/j.elspec.2012.02.004

► Ethynyl terpyridines were clicked to azide-terminated SAMs on gold. ► Azides and clicked terpyridines were characterized by N and C K-NEXAFS and N 1s XPS. ► S 1s+S 2p XPS was used to characterize the buried gold–sulfur interface of the SAM. ► Higher click reaction temperature leads to an increased amount of terpyridyl groups. ► Introduced terpyridyl groups are accessible for Pd(II) ion coordination. An ethynylterpyridine was “clicked” to an azide-terminated self-assembled monolayer on gold and characterized by synchrotron radiation based surface analysis as NEXAFS and XPS. The detection of azide and terpyridine signatures confirmed a partial click reaction at room temperature. The absence of the azides after reaction at 50°C indicates an almost complete conversion. For the latter case successful Pd(II) coordination has been proven. The Au–S interface of the SAMs has been characterized by S 1s and S 2p XPS.