Perfluoroalkylated Calix[4]pyrroles: Fluoride Ion Extraction from an Aqueous Medium. Issue 18 (28th August 2017)

• Record Type: Journal Article
• Authors: Maji, Sinchan; Mandal, Debaprasad
• Is Part Of: Chemistry, an Asian journal. Volume 12:Issue 18(2017)
• Page Start: 2369
• Page End: 2373
• Publication Date: 2017-08-28
• Subjects: anions -- calixpyrroles -- fluorides -- Hofmeister bias -- perfluoroalkyl groups; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/asia.201700897
• Languages: English
• ISSNs: 1861-4728

Abstract

Abstract: Octaalkenyl calix[4]pyrrole ((CH2 =CH(CH2 )2 )8 C4P) is highly useful for the postfunctionalization of different calix[4]pyrroles with desired functionalities. Functionalization with perfluoroalkyl chains [CF3 (CF2 ) n ; Rf n ] gave perfluoroalkyl calix[4]pyrroles (Rf n (CH2 )4 )8 C4P; n =6, 8), having >60 % fluorine content, which created a hydrophobic environment inside the calix[4]pyrrole cavity and recognized fluoride and chloride ions in solution as well as in the solid state. The fluoride ion is extracted efficiently from aqueous CsF and TBAF solutions by using (Rf6 (CH2 )4 )8 C4P, as droplets. The fluorinated chain generated a hydrophobic environment which broke the hydration shell associated with the anion and separated out fluoride ions as droplets from aqueous medium. Furthermore, the fluoride ions competitively replaced chloride ions from the (Rf6 (CH2 )4 )8 C4P cavity. Abstract : Fluoride anion extraction from water : Perfluoroalkyl substituted calix[4]pyrroles can entrap fluoride ions in their hydrophobic cavity, and separate from the aqueous solution as droplets, by breaking the hydration shell and overcoming the Hofmeister bias.