Analytical Sciences

Abstract − Analytical Sciences, 19(7), 991 (2003).

Potentiometric Response Mechanism of aPoly(acrylamide)-phthalocyaninato Tin(II) Film Coated Platinum Electrode inAcetonitrile and N,N-Dimethylacetamide
Toshio NAKAMURA,  JujieREN, Teruo HINOUE, and Kisaburo UMEMOTO
Department of Chemistry, Faculty ofScience, Shinshu University, Asahi, Matsumoto 390-8621, Japan
A new sensor constructed by a platinumelectrode coated with a non-plasticized poly(acrylamide) polymer (PAA) filmcoupled with phthalocyaninato tin(II) ([Sn(II)(pc)]) was developed. Thepotentiometric response behavior of this PAA-[Sn(II)(pc)] electrode forsuch anions as CN-, F-, Cl-, andBr- in dimethylacetamide and acetonitrile were investigated.The electrode showed a Nernstian response to CN- andF- and a quite poor response to Cl- andBr-. The mechanism of the peculiar selective response wasstudied by cyclic voltammetric and spectrophotometric methods. Thevoltammetric investigation suggested that the charge of the host compoundin the sensor membrane had no effect on the potential response of theelectrode. It was also found by a spectrophotometric investigation thatthe complexing of [Sn(II)(pc)] with CN- and F- leadto the selective response of the electrode. The motive force of thecomplexing was considered to be a ligand exchange of CN- orF- with molecules at the axial site of [Sn(II)(pc)] due tosolvent effects to the interest anions.