Phosphonium and Ammonium Ionic Liquids with Aromatic Anions: Synthesis, Properties, and Platinum Extraction*

Anja Stojanovic; Daniel Kogelnig; Lisa Fischer; Stephan Hann; Markus Galanski; Michael Groessl; Regina Krachler; Bernhard K. Keppler

doi:10.1071/CH09340

RESEARCH ARTICLE

Phosphonium and Ammonium Ionic Liquids with Aromatic Anions: Synthesis, Properties, and Platinum Extraction*

Anja Stojanovic ^A ^D ^E , Daniel Kogelnig ^A ^D , Lisa Fischer ^B , Stephan Hann ^B , Markus Galanski ^A , Michael Groessl ^C , Regina Krachler ^A and Bernhard K. Keppler ^A

+ Author Affiliations

- Author Affiliations

^A University of Vienna, Department of Inorganic Chemistry, Waehringer Strasse 42, 1090, Vienna, Austria.

^B Department of Chemistry, Division of Analytical Chemistry, University of Natural Resources and Applied Life Sciences, Muthgasse 18, 1190, Vienna, Austria.

^C Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland.

^D Both authors contributed equally to this work.

^E Corresponding author. Email: anja.stojanovic@univie.ac.at

Australian Journal of Chemistry 63(3) 511-524 https://doi.org/10.1071/CH09340
Submitted: 17 June 2009 Accepted: 26 August 2009 Published: 26 March 2010

Abstract

Several hydrophobic long-chain quaternary ammonium and phosphonium ionic liquids (ILs) with functionalized aromatic anions were prepared following a metathesis route using tricaprylmethylammonium chloride (Aliquat 336) and trihexyl(tetradecyl)phosphonium chloride (Cyphos IL101) as precursors. The incorporation of aromatic anions bearing hydroxy-, methoxy-, thiol-, and thioether functionalities as well as tetraphenylborate anions resulted in an increased chemical stability of the ILs and an alteration of their physico-chemical properties. Furthermore, aromatic anions significantly decreased the water solubility and water uptake of both ammonium and phosphonium-based ILs. Thiol- and thioether ILs were applied for the extraction of platinum from aqueous phase using liquid phase micro-extraction. Time dependent studies showed a rapid elimination of up to 95% platinum after 30 min. With a leaching of the anion <0.01 wt-% into the aqueous media, the evaluated ILs were found to be suitable as extracting agents for platinum from aqueous solutions.

Acknowledgements

The authors are grateful to Professor Peter Unfried, Institute of Inorganic Chemistry, University of Vienna, for conducting TGA measurements, Professor Gerhard Schleining, Department of Food Sciences and Technology, University of Natural Resources and Applied Life Sciences, Vienna, for his assistance in viscosity measurements and the Austrian Federal Ministry of Agriculture, Forestry, Environment and Water Management (Project number A600702) for the financial support.

References

^* This paper is based on the poster “Thioether-functionalized ionic liquids and their task specificity for platinum uptake using liquid phase micro-extraction” presented at COIL₃, 3rd Congress on Ionic Liquids, May 31–June 4 2009, Cairns, Australia.

Phosphonium and Ammonium Ionic Liquids with Aromatic Anions: Synthesis, Properties, and Platinum Extraction*

Abstract

Acknowledgements

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