Direct Detection of the Ion Pair to Free Ions Transformation upon Complexation with an Ion Receptor in Non‐Polar Solvents by using Conductometry. Issue 3 (30th March 2018)

• Record Type: Journal Article
• Authors: Iseda, Kazuya; Kokado, Kenta; Sada, Kazuki
• Is Part Of: ChemistryOpen. Volume 7:Issue 3(2018)
• Page Start: 269
• Page End: 274
• Publication Date: 2018-03-30
• Subjects: anions -- host–guest systems -- molecular recognition -- receptors -- supramolecular chemistry; Chemistry -- Periodicals; 540; 540.5
• DOI: 10.1002/open.201800014
• Languages: English
• ISSNs: 2191-1363

Abstract

Abstract: In this study, we performed conductometry in various organic solvents to directly detect the transformation from tetrabutylammonium chloride (TBACl ) ion‐pair salt to the free ions through complexation with meso ‐octamethylcalix[4]pyrrole (CP ), which is a well‐known receptor for chloride anions. In the presence ofCP, the conductivity ofTBACl increases in various non‐polar solvents, indicating that complexation withCP enhances the ionic dissociation ofTBACl in such non‐polar solvents. In other words, CP recognizes chloride as an ion‐paired salt as well as a free anion in non‐polar solvents. Additionally, theTBA(CP –Cl ) complex exhibited a considerably lower ion‐pairing constant ( K ip ) thanTBACl in non‐polar solvents, resulting in enhanced conductivity. Based on these findings, we can conclude that complexation of an anion with a hydrophobic anion receptor will be useful for creating functional and stimuli‐responsive soft materials in organic solvents using coulombic forces. Abstract : From ion pairs to free ions : Direct detection of the transformation from the ion‐pair salt of tetrabutylammonium chloride to free chloride anions is demonstrated through complexation with an anion receptor, meso ‐octamethylcalix[4]pyrrole, by using conductometry in various organic solvents.