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Updated: Jun 8, 2025
From Molecules to Materials: Engineering New Ionic Liquid Crystals Through Halogen Bonding
Published on: March 24, 2018
Dichlorine-pyridine N-oxide halogen-bonded complexes
Niklas Limberg1, J Mikko Rautiainen2, Jan Lundell2
1Department of Chemistry and Biochemistry, Freie Universität Berlin Fabeckstr. 34/36 14195 Berlin Germany s.riedel@fu-berlin.de.
Abstract:
A new Cl-Cl···-O-N+ halogen-bonded paradigm has been demonstrated, using dichlorine as a halogen bond (XB) donor and N-oxide as an XB acceptor. Their crystalline complexes were formed during the warm-up process from -196 °C to -80 °C for X-ray diffraction analysis. They exhibit high instability in the crystalline state, even at these low temperatures, leading to rapid decomposition and the formation of Cl⋯H-O-N hydrogen-bonded complexes. The normalized XB interaction ratio (R XB) of Cl⋯O interactions in the solid-state demonstrates affinity comparable to traditional I⋯O interactions observed in I-I···-O-N+ halogen-bonded systems. The Cl-Cl⋯O XB angles vary from 172° to 177°, manifesting the structure-guiding influence of the electronegative chlorine atom's σ-hole on these XB interactions.
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