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Updated: Mar 22, 2026

From Molecules to Materials: Engineering New Ionic Liquid Crystals Through Halogen Bonding
Published on: March 24, 2018
CF3 : An Electron-Withdrawing Substituent for Aromatic Anion Acceptors? "Side-On" versus "On-Top" Binding of Halides
Markus Albrecht1, Hai Yi2, Okan Köksal2
1Institut für Organische Chemie, RWTH Aachen, Landoltweg 1, 52074, Aachen, Germany. markus.albrecht@oc.rwth-aachen.de.
Abstract:
The ability of multiple CF3 -substituted arenes to act as acceptors for anions is investigated. The results of quantum-chemical calculations show that a high degree of trifluoromethyl substitution at the aromatic ring results in a positive quadrupole moment. However, depending on the polarizability of the anion and on the substitution at the arene, three different modes of interaction, namely Meisenheimer complex, side-on hydrogen bonding, or anion-π interaction, can occur. Experimentally, the side-on as well as a η(2) -type π-complex are observed in the crystal, whereas in solution only side-on binding is found.
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