Ferrocenyl-sulfonium ionic liquids - synthesis, characterization and electrochemistry

Area of Science:

• Organometallic Chemistry
• Electrochemistry
• Materials Science

Background:

• Ionic liquids (ILs) are versatile materials with tunable properties.
• Ferrocene-based compounds offer unique redox activity.
• Developing novel ILs for energy storage and conversion is crucial.

Purpose of the Study:

• To synthesize novel ferrocenylsulfonium cation-based ionic liquids.
• To investigate their redox properties and potential applications in energy devices.
• To explore the influence of the sulfonium group on ferrocene redox potential.

Main Methods:

• Direct alkylation of ferrocenyl-based thioethers with N-alkylbis(trifluoromethanesulfonyl)imides.
• X-ray diffraction (XRD) for solid-state analysis.
• Cyclic voltammetry for redox chemistry investigation.
• UV-Vis spectroscopy and thermoanalytical methods.

Main Results:

• Successful synthesis of highly pure, redox-active room temperature ionic liquids.
• Demonstrated influence of the electron-withdrawing sulfonium group on redox potential.
• Characterization of a diferrocenylmethylsulfonium tetrafluoroborate with two redox centers.
• Analysis of anion-cation interactions in the solid state via XRD.

Conclusions:

• The synthesized ferrocenylsulfonium ILs exhibit reversible and tunable redox potentials.
• Their low visible light absorbance and electrochemical properties make them suitable for energy applications.
• These ILs show promise as redox mediators in dye-sensitized solar cells, electrolytes in supercapacitors, and additives in batteries.