Single Side Strapping: A New Approach to Fine Tuning the Anion Recognition Properties of Calix[4]pyrroles
Autor: | Hee Kyung Na, Vincent M. Lynch, Jonathan L. Sessler, Chang-Hee Lee, Dong Hoon Won, Won Seob Cho, Dae Wi Yoon, Sergey V. Shevchuk |
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Rok vydání: | 2003 |
Předmět: |
Anions
Models Molecular Magnetic Resonance Spectroscopy Porphyrins Stereochemistry Crystallography X-Ray Biochemistry Chloride Catalysis chemistry.chemical_compound Colloid and Surface Chemistry Molecular recognition Bromide Calixarene medicine Pyrroles Anion binding Acetonitrile Molecular Structure Chemistry Isothermal titration calorimetry Resorcinols General Chemistry Affinities Crystallography Calixarenes medicine.drug |
Zdroj: | Journal of the American Chemical Society. 125:7301-7306 |
ISSN: | 1520-5126 0002-7863 |
DOI: | 10.1021/ja029175u |
Popis: | Three calix[4]pyrroles bearing m-orcinol-derived diether straps of different lengths on one side of the tetrapyrrolic core have been synthesized and characterized. Structural information for an analogous diester bridged strapped system reported previously (Yoon, D. W.; Hwang, H.; Lee, C. H. Angew. Chem., Int. Ed. Engl. 2002, 41, 1757-1759) is also provided as are bromide and chloride anion affinities for all four systems determined by Isothermal Titration Calorimetry (ITC) in acetonitrile. Although both sets of the strapped calix[4]pyrroles displayed enhanced affinities for chloride and bromide anion, differences were seen among the various receptors that support the conclusion that the anion binding ability of calixpyrrole-type systems can be effectively tuned by modifying the length and nature of the bridging straps. In the specific case of the diether systems, the largest chloride affinity was seen with the shortest strap, whereas the largest affinity for bromide anion was recorded in the case of the longest strap. On the basis of these findings, as well as supporting (1)H NMR spectroscopic studies, it is postulated that not only cavity size per se, but also the ability of the aryl portion of the strap to serve as a CH hydrogen bond donor site are important in regulating the observed anion affinities. |
Databáze: | OpenAIRE |
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