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Updated: Jan 25, 2026

From Molecules to Materials: Engineering New Ionic Liquid Crystals Through Halogen Bonding
Published on: March 24, 2018
The pentafluoroethyltrihydridoborate anion: from shock sensitive salts to stable room temperature ionic liquids
P T Hennig1, J A P Sprenger1, L N Schneider1
1Universität Würzburg, Institut für Anorganische Chemie, Institut für nachhaltige Chemie & Katalyse mit Bor (ICB), Am Hubland, 97074 Würzburg, Germany. maik.finze@uni-wuerzburg.de.
Abstract:
The reaction of pentafluoroethyllithium with BH3·thf yields [C2F5BH3]- that is stable against H2O, OH- and air due to the electron withdrawing C2F5 group. M[C2F5BH3] (M = K, Cs) are shock sensitive solids whereas salts with organic cations such as the room temperature ionic liquid [EMIm][C2F5BH3] are stable for years. [C2F5BH3]- is a mild reducing agent, which is also reflected by its electrochemical properties. Oxidation with I2 or Br2 in the presence of Lewis bases yields the first stable adducts C2F5BH2·L.
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