| Zugriffsnummer | 48844 |
| Dokumenttyp | Zeitschriftenartikel |
| Peer Review | mit Peer Review |
| Sprache | Englisch |
| Titel | Structure and stability of 7-mercapto-4-methylcoumarin self-assembled monolayers on gold: an experimental and computational analysis |
| Autor(in); Institution |
Marchi, Davide; Dipartimento di Scienze e Innovazione Tecnologica (DISIT), Universita del Piemonte Orientale, Alessandria, ITALY
Cara, Eleonora; Istituto Nazionale di Ricerca Metrologica (INRiM), Torino, ITALY
Ferrarese Lupi, Federico; Istituto Nazionale di Ricerca Metrologica (INRiM), Torino, ITALY
Beckhoff, Burkhard; 7.2, Röntgenmesstechnik mit Synchrotronstrahlung, PTB-Berlin
Castellino, Micaela; Department of Applied Science and Technology, Politecnico di Torino, Turin, ITALY
Klapetek, Petr; Department of Nanometrology, Czech Metrology Institute,Brno, CZECH REPUBLIC
Zoccante, Alberto; Dipartimento di Scienze e Innovazione Tecnologica (DISIT), Universita del Piemonte Orientale, Alessandria, ITALY
Laus, Michele; Dipartimento di Scienze e Innovazione Tecnologica (DISIT), Universita del Piemonte Orientale, Alessandria, ITALY
Cossi, Maurizio; Dipartimento di Scienze e Innovazione Tecnologica (DISIT), Universita del Piemonte Orientale, Alessandria, ITALY
|
| Quelle/Jahr | Physical Chemistry, Chemical Physics: 24 (2022), 36, 22083 - 22090 |
| ISSN | 1463-9076 (ONLINE) |
| DOI | |
| Verlag | Berlin: Royal Society of Chemistry |
| Zusammenfassung | Self-assembled monolayers (SAM) of 7-mercapto-4-methylcoumarin (MMC) on a flat gold surface were studied by molecular dynamics (MD) simulations, reference-free grazing incidence X-ray fluorescence (GIXRF) and X-ray photoelectron spectroscopy (XPS), to determine the maximum monolayer density and to investigate the nature of the molecule/surface interface. In particular, the protonation state of the sulfur atom upon adsorption was analyzed, since some recent literature presented evidence for physisorbed thiols (preserving the S–H bond), unlike the common picture of chemisorbed thiyls (losing the hydrogen). MD with a specifically tailored force field was used to simulate either thiol or thiyl monolayers with increasing number of molecules, to determine the maximum dynamically stable densities. This result was refined by computing the monolayer chemical potential as a function of the density with the bennet acceptance ratio method, based again on MD simulations. The monolayer density was also measured with GIXRF, which provided the absolute quantification of the number of sulfur atoms in a dense self-assembled monolayer (SAM) on flat gold surfaces. The sulfur core level binding energies in the same monolayers were measured by XPS, fitting the recorded spectra with the binding energies proposed in the literature for free or adsorbed thiols and thiyls, to get insight on the nature of the molecular species present in the layer. The comparison of theoretical and experimental SAM densities, and the XPS analysis strongly support the picture of a monolayer formed by chemisorbed, dissociated thiyls. |
| Kostenfreier Zugang | Open Access Hybrid |
| Rechteinformation | CC BY-NC 4.0 ; Creative Commons Attribution NonCommercial 4.0 License |
| Themenbereich der Metrologie | Photometrie und Radiometrie |
Zitierung
Marchi, D., Cara, E., Ferrarese Lupi, F., Hönicke, P., Kayser, Y., Beckhoff, B., Castellino, M., Klapetek, P., Zoccante, A., Laus, M., & Cossi, M. (2022). Structure and stability of 7-mercapto-4-methylcoumarin self-assembled monolayers on gold: an experimental and computational analysis. Physical Chemistry, Chemical Physics, 24(36), 22083–22090. https://doi.org/10.1039/d2cp03103e