Molecular "pincer" from a diimidazolium salt: a study of binding ability.
The anion recognition ability of the dicationic imidazolium salt 3,3'-di-n-octyl-1,1'-(1,3-phenylenedimethylene)diimidazolium 1,5-naphthalenedisulfonate ([m-Xyl-(oim)2][1,5-NDS]) was investigated in acetonitrile solution by means of proton NMR titrations. A wide range of anions, comprising simple inorganic ions, halides, and mono- and dicarboxylates was taken into account. The study showed that this receptor binds carboxylate anions more strongly than halides. Moreover [m-Xyl-(oim)2][1,5-NDS] displays selectivity for di- over monocarboxylate anions. The complex stability was mainly affected by the anion basicity in the presence of monocarboxylates, whereas the flexibility of the alkyl chain linking the two carboxylate moieties appeared to play a major role in the presence of dicarboxylate anions.
Sezione di Chimica, Dipartimento STEBICEF, Università degli Studi di Palermo , Viale delle Scienze-Parco d'Orleans II, 90128 Palermo, Italy.
Salvatore
S
Marullo
Francesca
F
D'Anna
Marco
M
Cascino
Renato
R
Noto
D002264:Carboxylic Acids / Q000737:chemistry*; D006860:Hydrogen Bonding; D007093:Imidazoles / Q000737:chemistry*; D007477:Ions / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D009282:Naphthalenesulfonates / Q000737:chemistry*; D012492:Salts
C000588944:3,3'-di-n-octyl-1,1'-(1,3-phenylenedimethylene)diimidazolium 1,5-naphthalenedisulfonate; D002264:Carboxylic Acids; D007093:Imidazoles; D007477:Ions; D009282:Naphthalenesulfonates; D012492:Salts; C029899:imidazole