Structure and stability of 7-mercapto-4-methylcoumarin self-assembled monolayers on gold: an experimental and computational analysis

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00177016%3A_____%2F22%3AN0000086" target="_blank" >RIV/00177016:_____/22:N0000086 - isvavai.cz</a>

Result on the web

<a href="https://pubs.rsc.org/en/content/articlelanding/2022/cp/d2cp03103e" target="_blank" >https://pubs.rsc.org/en/content/articlelanding/2022/cp/d2cp03103e</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1039/D2CP03103E" target="_blank" >10.1039/D2CP03103E</a>

Result language

angličtina

Original language name

Structure and stability of 7-mercapto-4-methylcoumarin self-assembled monolayers on gold: an experimental and computational analysis

Original language description

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.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10403 - Physical chemistry

Project

—

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2022

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Physical Chemistry Chemical Physics

ISSN

1463-9084

e-ISSN

—

Volume of the periodical

24

Issue of the periodical within the volume

05 Sep 2022

Country of publishing house

GB - UNITED KINGDOM

Number of pages

8

Pages from-to

22083–22090

UT code for WoS article

000850825900001

EID of the result in the Scopus database

2-s2.0-85138458483