Potentiometric performance of silver ion-selective electrodes based on tridentate Schiff base derivatives.
To examine the directivity for improving the silver ion discrimination ability of a Schiff base, three kinds of tridentate ligands were synthesized and compared with the similar quadridentate ligand as the silver ionophore. Among the Schiff base derivatives tested, 3-(2-pyridylethylimino)-2-butanoneoxime, having one oxime and a pyridine substituent, was found to be the best ionophore for a silver-ion electrode. The electrode based on this derivative exhibited good silver-ion selectivity, -log Kpot(Ag+,K+) = 3.8, comparable to that of a quadridentate Schiff base, N,N'-bis(2'-hydroxyimino-1'-phenylpropyleden)-1,3-propanediamine, reported previously, except for a pseudo Nernstian response (35.6 mV decade(-1)) with a wide silver-ion activity change in the activity change from 5.0 x 10(-7) to 7.9 x 10(-2) mol dm(-3).
Ueda
Masato
M
Department of Applied Chemistry, Faculty of Engineering, Osaka Institute of Technology, 5-16-1, Omiya, Asahi, Osaka 535-8585, Japan. ueda@k7.chem.oit.ac.jp
Saito
Takahiro
T
Fujimori
Keiichi
K
Moriuchi
Takayo
T
Shibutani
Yasuhiko
Y