Analysis of Complex Formation Equilibrium of Phenylalkylammonium Ions with 18-Crown-6 by Capillary Zone Electrophoresis

作者：Inoue Genki^*; Takayanagi Toshio

来源：Bunseki Kagaku, 2010, 59(8): 709-713.

DOI：10.2116/bunsekikagaku.59.709

• phenylalkylammonium ions
• 18-crown-6
• complex formation equilibrium
• capillary zone electrophoresis
• intermolecular interactions

Complex formation equilibrium of phenylalkylammonium ions (PAA(+)) with 18-crown-6 (18C6) has been analyzed by capillary zone electrophoresis (CZE). The electrophoretic mobility of PAA(+) (mu(ep)') was measured by CZE in the presence of 18C6 in a migrating buffer, and the mu(ep)' values were used for equilibrium analysis. The mu(ep)' values decreased with increasing concentrations of 18C6, and 1 : 1 complex formation constants, K, were determined. The K values for PAA(+) in an aqueous solution are comparable to literature data reported for the ammonium ion. The K values increased with a longer alkyl chain in PAA(+), except for the benzylammonium ion. The results suggested the contribution of hydrophobicity in PAA(+), as well as CH/pi interactions for the benzylammonium ion. The K values also increased in mixed aqueous solvents with a decreased dielectric constant, which suggested the contribution of ion-dipole interaction in the complex formation reaction.

• 出版日期2010-8