A1 Journal article (refereed)
Anion Responsive Molecular Switch Based on a Doubly‐Strapped Calix[4]pyrrole (2022)

Helttunen, K. (2022). Anion Responsive Molecular Switch Based on a Doubly‐Strapped Calix[4]pyrrole. European Journal of Organic Chemistry, 2022(42), Article e202200647. https://doi.org/10.1002/ejoc.202200647

JYU authors or editors

Publication details

All authors or editorsHelttunen, Kaisa

Journal or seriesEuropean Journal of Organic Chemistry



Publication year2022

Publication date15/08/2022


Issue number42

Article numbere202200647

PublisherWiley-VCH Verlag

Publication countryGermany

Publication languageEnglish


Publication open accessOpenly available

Publication channel open accessPartially open access channel

Publication is parallel published (JYX)https://jyx.jyu.fi/handle/123456789/83896


A calix[4]pyrrole receptor bearing two proximally meso - meso linking isophthaloyl straps displays open and closed states depending on the calix[4]pyrrole conformation. In the crystal structures and in non-polar solvent, the calix[4]pyrrole adopts open 1,3-alternate conformation with straps on the sides. Anion binding triggers a closed state of the receptor providing two types of interactions with an aromatic benzoate guest: hydrogen bonds from the pyrrolic groups and π ··· π interactions from the phenyl groups of the straps. Slow exchange dynamics was observed on the NMR timescale indicating that benzoate, acetate and chloride anions, which bind with relatively low affinity get kinetically trapped in the receptor as insects in a Venus flytrap .

Keywordsheterocyclic compoundschemical bondshydrogen bondsanionssupramolecular chemistryNMR spectroscopy

Free keywordsanions; calix[4]pyrroles; molecular switch; NMR spectroscopy; supramolecular chemistry

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Related projects

Ministry reportingYes

Reporting Year2022

JUFO rating1

Last updated on 2024-30-04 at 17:26