Influence of ionic liquid composition on surface enrichment of fluorine-free Ru complexes

Ceccatto dos Santos A, Sanchez Merlinsky L, Baraldo LM, Williams FJ, Maier F, Steinrück HP (2025)

Publication Language: English

Publication Type: Journal article

Publication year: 2025

Journal

RSC Advances Royal Society of Chemistry

Book Volume: 15

Pages Range: 36137-36144

Journal Issue: 43

DOI: 10.1039/d5ra05316a

Abstract

Tailoring the surface composition of ionic liquids (ILs) is a key strategy for enhancing the performance of supported ionic liquid phase (SILP) catalysts. Here, we investigate the interfacial behavior of fluorine-free Ru polypyridyl complexes functionalized with n-nonyl side chains (Ru-C9) dissolved in two ILs with contrasting physicochemical properties, such as hydrophobicity and surface tension, namely [C4C1Im][PF6] and [C4C1Im][OAc]. Using angle-resolved X-ray photoelectron spectroscopy (ARXPS), we show that Ru-C9 complexes undergo pronounced surface enrichment in [C4C1Im][PF6], adopting a buoy-like orientation at the IL/vacuum interface. Surface saturation is achieved at a bulk concentration of 0.12%mol, a regime relevant for efficient SILP catalysis. In contrast, no interfacial enrichment is observed in [C4C1Im][OAc], highlighting the critical role of IL composition, particularly anion identity and surface tension, in governing the surface distribution of metal complexes. These findings provide molecular-level insights into the design of IL-based catalytic systems with optimized interfacial properties.

Authors with CRIS profile

Alisson Ceccatto dos Santos Lehrstuhl für Physikalische Chemie II Florian Maier Lehrstuhl für Physikalische Chemie II Hans-Peter Steinrück Lehrstuhl für Physikalische Chemie II

Involved external institutions

Universidad de Buenos Aires (UBA) / University of Buenos Aires AR Argentina (AR)

How to cite

APA:

Ceccatto dos Santos, A., Sanchez Merlinsky, L., Baraldo, L.M., Williams, F.J., Maier, F., & Steinrück, H.-P. (2025). Influence of ionic liquid composition on surface enrichment of fluorine-free Ru complexes. RSC Advances, 15(43), 36137-36144. https://doi.org/10.1039/d5ra05316a

MLA:

Ceccatto dos Santos, Alisson, et al. "Influence of ionic liquid composition on surface enrichment of fluorine-free Ru complexes." RSC Advances 15.43 (2025): 36137-36144.

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