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Updated: Oct 16, 2025

From Molecules to Materials: Engineering New Ionic Liquid Crystals Through Halogen Bonding
Published on: March 24, 2018
Investigation of Bis(Perfluoro-tert-Butoxy) Halogenates(I/III)
Patrick Pröhm1, Willi R Berg1, Susanne M Rupf1
1Department of Chemistry and Biochemistry-Inorganic Chemistry, Freie Universität Berlin, Fabeckstrasse 34/36, 14195, Berlin, Germany.
Abstract:
A systematic study of halogenate(I/III) anions with polyatomic ligands is presented. The bis(perfluoro-tert-butoxy) halogenates(I) [X(OC4 F9 )2 ]- , X=Cl, Br, I, of chlorine, bromine, and iodine are prepared as their tetraethylammonium salts and characterized with IR, Raman, and NMR spectroscopic methods, as well as single-crystal X-ray diffraction analyses. Spectroscopical data are supported by quantum-chemical calculations. Additionally, the bonding situation of the species in question are analyzed and discussed. Furthermore, the oxidation to the corresponding halogenate(III) derivatives was studied. For [Br(OC4 F9 )2 ]- , oxidation with elemental fluorine gave [BrF2 (OC4 F9 )2 ]- . Iodide was directly oxidized by ClOC4 F9 to the IIII species [I(OC4 F9 )4 ]- , which is a surprisingly inert anion that might be used as a weakly coordinating anion (WCA) in the future. For [Cl(OC4 F9 )2 ]- , the decomposition products of the synthetic approaches towards a chlorine(III) system were analyzed.
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