Ion‐Pair Recognition of Tetramethylammonium Salts by Halogenated Resorcinarenes |
| |
Authors: | Dr. N. Kodiah Beyeh Dominik P. Weimann Lena Kaufmann Prof. Dr. Christoph A. Schalley Prof. Kari Rissanen |
| |
Affiliation: | 1. Department of Chemistry, University of Jyv?skyl?, P. O. Box 35, 40014 Jyv?skyl? (Finland), Fax: (+358)?142‐602‐501;2. Institut für Chemie und Biochemie—Organische Chemie, Freie Universit?t Berlin, Takustr. 3, 14195 Berlin (Germany), Fax: (+49)?308‐385‐5817 |
| |
Abstract: | The non‐covalent interactions of different upper‐rim‐substituted C2‐resorcinarenes with tetramethylammonium salts were analyzed in the gas phase in an Electrospray Ionization Fourier‐transform ion‐cyclotron‐resonance (ESI‐FTICR) mass spectrometer and by 1H NMR titrations. The order of binding strengths of the hosts towards the tetramethylammonium cation in the gas phase reflects the electronic nature of the substituents on the upper rim of the resorcinarene. In solution, however, a different trend with particularly high binding constants for halogenated resorcinarenes has been observed. This trend can be explained by a synergetic effect originating from the interaction of the halogenated resorcinarenes with the counter anions through hydrogen bonding. This study highlights the importance of weak interactions in recognition processes and points out the benefits of comparing the gas‐phase data with results obtained from solution experiments. |
| |
Keywords: | host– guest systems ion‐pair recognition mass spectrometry NMR spectroscopy resorcinarenes |
|
|