American Chemical Society
ja9b08257_si_001.pdf (1.64 MB)

Cooperative Silver Ion-Pair Recognition by Peralkylated Pillar[5]arenes

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journal contribution
posted on 2019-09-16, 18:04 authored by Bin Hua, Li Shao, Zhihua Zhang, Jiyong Liu, Feihe Huang
Ion-pair recognition of metal salts by pillararenes has never been reported. This limits the further development and applications of pillararene supramolecular chemistry. Herein we report the first examples of pillararene-based metal ion-pair recognition. They are host–guest complexes between three peralkylated pillar[5]­arenes and the silver salt CF3COOAg. Single crystal X-ray analysis shows that CF3COOAg forms a unique dinuclear silver structure that penetrates into the pillar[5]­arene cavity in these complexes. Besides the silver-π interactions, multiple C–H···O and C–H···F hydrogen bonds between the counterion and the pillar[5]­arene host also contribute to stabilizing and maintaining the host–guest structures. Moreover, benefiting from the silver ion-pair recognition, perethylated pillar[5]­arene EtP5 can be used as a solid absorbent to capture CF3COOAg from solution efficiently, showing a potential application in precious metal extraction and recycling.