On‐Surface Metathesis of an Ionic Liquid on Ag(111)

Language
en
Document Type
Article
Issue Date
2022-06-15
First published
2022-05-16
Issue Year
2022
Authors
Massicot, Stephen
Sasaki, Tomoya
Lexow, Matthias
Maier, Florian
Kuwabata, Susumu
Steinrück, Hans‐Peter
Editor
Publisher
Wiley-VCH GmbH
Abstract

Abstract We investigated the adsorption, surface enrichment, ion exchange, and on‐surface metathesis of ultrathin mixed IL films on Ag(111). We stepwise deposited 0.5 ML of the protic IL diethylmethylammonium trifluoromethanesulfonate ([dema][TfO]) and 1.0 ML of the aprotic IL 1‐methyl‐3‐octylimidazolium hexafluorophosphate ([C8C1Im][PF6]) at around 90 K. Thereafter, the resulting layered frozen film was heated to 550 K, and the thermally induced phenomena were monitored in situ by angle‐resolved X‐ray photoelectron spectroscopy. Between 135 and 200 K, [TfO]− anions at the Ag(111) surface are exchanged by [PF6]− anions and enriched together with [C8C1Im]+ cations at the IL/vacuum interface. Upon further heating, [dema][PF6] and [OMIm][PF6] desorb selectively at ∼235 and ∼380 K, respectively. Hereby, a wetting layer of pure [C8C1Im][TfO] is formed by on‐surface metathesis at the IL/metal interface, which completely desorbs at ∼480 K. For comparison, ion enrichment at the vacuum/IL interface was also studied in macroscopic IL mixtures, where no influence of the solid support is expected.

Journal Title
Chemistry – A European Journal
Volume
28
Issue
28
Citation
Chemistry – A European Journal 28.28 (2022): e202200167. <https://chemistry-europe.onlinelibrary.wiley.com/doi/10.1002/chem.202200167>