123rd General Meeting of the KCS

Type Poster Presentation
Area Organic Chemistry
Room No. Exhibition Hall 2
Time 4월 18일 (목요일) 11:00~12:30
Code ORGN.P-156
Subject Synthesis of a crown ether strapped-hexapyrrolic calix[4]pyrrole with amide linkage and its anion and ion pair recognition
Authors Nam Jung Heo, Sung Kuk Kim*
Department of Chemistry, Gyeongsang National University, Korea
Abstract The hexapyrrolic calix[4]pyrrole strapped with a crown ether via amide linkages was synthesized. 1H NMR spectroscopic analyses revealed that the receptor was able to various anions such as the fluoride, the chloride, and the hydrogen phosphate anion with remarkably high affinity. This finding was ascribed to all of eight NHs playing a role in anion binding. It was also proved that the receptor bound the fluoride and the chloride anion in different binding modes. For example, in the case of the former anion, the pyrroles attached to the meso carbon of the calix[4]pyrrole framework take part in the fluoride binding via π-anion interaction. By contrast, the meso pyrroles participate in the binding of the chloride anion forming direct hydrogen bonds. The receptor was also found to bind LiCl and CsCl with high affinity. In this case, the lithium cation was complexed with the crown moiety while the chloride anion was hydrogen bonded to the NHs of the calix[4]pyrrole and the meso pyrroles as well as the amide NHs. On the contrary, in the case of CsCl, the cesium cation was presumed to be bound to the bowl shape of the calix[4]pyrrole cavity conformationally fixed as a result of the chloride binding.
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