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Updated: Jun 12, 2025
From Molecules to Materials: Engineering New Ionic Liquid Crystals Through Halogen Bonding
Published on: March 24, 2018
Halogen Bonding in N-Alkyl-Bromo-/Lodo-Pyridinium Salts and its Application in Chromatography
Peter Wendt1, Julia Bader1, Paul L Waltersmann1
1Center for Molecular Materials, Inorganic Chemistry and Structural Chemistry Bielefeld University, Universitätsstraße 25, 33615, Bielefeld, Germany.
Abstract:
The alkylation of 3-/4-bromo- and -iodopyridine with methyl triflate smoothly affords the corresponding N-methylpyridinium triflate salts. An anion exchange with NaI or [PPh4]Y (Y=Cl, Br, I) yields the corresponding halide salts. Most of them could be structurally characterized and their strong halogen bonds were investigated. While the halogen atom of 4-halogenopyridinium is susceptible to nucleophilic substitution, 3-halogenopyridinium ions are far more stable against nucleophilic attacks. Due to the comparable interaction strength of halogen bonds and hydrogen bonds, the latter of which is widely used in chromatography, the potential of 3-halogenopyridinium moieties for an application in chromatography is obvious and was successfully employed in affinity chromatography of different proteins.
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