Water-soluble p-sulfonatocalix[7]arene 1 has been synthesized in good yield through standard procedures and its conformational preferences have been investigated by Monte Carlo conformational searches. The acid–base properties of 1 were investigated by means of potentiometric titration, obtaining pKa values in agreement with those reported for other p-sulfonatocalix[n]arene homologs. The binding ability of 1 toward organic quaternary ammonium cations such as Diquat (2), Paraquat (3), and Chlormequat (4) was investigated by means of 1H NMR titrations in D2O at pD = 7.3, DOSY NMR measurements, and 2D ROESY NMR spectroscopy. Spectrofluorimetry proved to be a useful method for the determination of trace amounts of 2 and 3 in aqueous solution by using Acridine Orange bound to 1 as a chemical indicator.
p-Sulfonatocalix[7]arene: synthesis, protolysis and binding ability
GAETA, CARMINE;CARUSO, Tonino;TROISI, FRANCESCO;VASCA, Ermanno;NERI, Placido
2008-01-01
Abstract
Water-soluble p-sulfonatocalix[7]arene 1 has been synthesized in good yield through standard procedures and its conformational preferences have been investigated by Monte Carlo conformational searches. The acid–base properties of 1 were investigated by means of potentiometric titration, obtaining pKa values in agreement with those reported for other p-sulfonatocalix[n]arene homologs. The binding ability of 1 toward organic quaternary ammonium cations such as Diquat (2), Paraquat (3), and Chlormequat (4) was investigated by means of 1H NMR titrations in D2O at pD = 7.3, DOSY NMR measurements, and 2D ROESY NMR spectroscopy. Spectrofluorimetry proved to be a useful method for the determination of trace amounts of 2 and 3 in aqueous solution by using Acridine Orange bound to 1 as a chemical indicator.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
