Anion‐Exchange Properties of Trifluoroacetate and Triflate Salts of N‐Alkylammonium Resorcinarenes. Issue 5 (28th January 2016)

• Record Type: Journal Article
• Authors: Pan, Fangfang; Beyeh, Ngong Kodiah; Bertella, Stefania; Rissanen, Kari
• Is Part Of: Chemistry, an Asian journal. Volume 11:Issue 5(2016)
• Page Start: 782
• Page End: 788
• Publication Date: 2016-01-28
• Subjects: anion binding -- crystal engineering -- host–guest systems -- macrocycles -- weak interactions; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/asia.201501335
• Languages: English
• ISSNs: 1861-4728

Abstract

Abstract: The synthesis of N ‐benzyl‐ and N ‐cyclohexylammonium resorcinarene trifluoroacetate (TFA) and triflate (OTf) salt receptors was investigated. Solid‐state analysis by single‐crystal X‐ray diffraction revealed that the N ‐alkylammonium resorcinarene salts (NARSs) with different upper substituents had different cavity sizes and different affinities for anions. Anion‐exchange experiments by mixing equimolar amounts of N‐ benzylammonium resorcinarene trifluoroacetate and N ‐cyclohexylammonium resorcinarene triflate, as well as N‐ benzylammonium resorcinarene triflate and N ‐cyclohexylammonium resorcinarene trifluoroacetate showed that the NARS with flexible benzyl groups preferred the larger OTf anion, whereas the rigid cyclohexyl groups preferred the smaller TFA anions. The anion‐exchange processes were confirmed in the solid state by single‐crystal and powder X‐ray diffraction experiments and in the gas phase by electrospray ionization mass spectrometry. Abstract : How to host guests : The N ‐alkylammonium resorcinarene trifluoroacetate (TFA) and triflate (OTf) salts are synthesized. Flexible (benzyl) and rigid (cyclohexyl) upper rims in combination with the anions result in different cavity sizes and guest‐binding properties. The upper‐rim flexible benzyl groups prefer the larger OTf anion, whereas the rigid cyclohexyl groups prefer the smaller TFA anion, as observed from exchange experiments in the solid and gas phases.