Facile Synthesis of Anhydrous Rare-Earth Trichlorides from their Oxides in Chloridoaluminate Ionic Liquids

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Wide applications of anhydrous rare-earth (RE) trichlorides RECl3 in organometallic chemistry, for the synthesis of optical and magnetic materials, and as catalysts require a facile approach for their synthesis. The known methods use or produce toxic substances, are complicated and have limited reliability and upscaling. It has been shown that task-specific ionic liquids (ILs) can dissolve many metal oxides without special reaction conditions at moderate temperature, making the metals accessible to downstream chemistry. Using imidazolium chloridoaluminate ILs, pure crystalline anhydrous RECl3 (RE=La−Nd, Sm−Dy) can be synthesized in one step from RE oxides in high yield. The Lewis acidic IL acts as solvent and reaction partner. The by-product [Al4O2Cl10]2−, which was detected spectroscopically, remains in solution. The reacted IL can be removed quantitatively by washing. ILs with various imidazolium cations and AlCl3 content and the effect of temperature and reaction time were tested.


Original languageEnglish
Article numbere202317480
Number of pages7
JournalAngewandte Chemie - International Edition
Volume63 (2024)
Issue number4
Publication statusPublished - 14 Jan 2024

External IDs

PubMed 38059405
ORCID /0000-0002-2391-6025/work/159171977


ASJC Scopus subject areas


  • Anhydrous Chlorides, Ionic Liquids, Ionothermal Synthesis, One-Pot Synthesis, Rare Earths