M. Sekota et T. Nyokong, CATALYTIC BEHAVIOR OF OSMIUM(II), RHODIUM(III) AND RUTHENIUM(II) PHTHALOCYANINES TOWARDS THE ELECTROOXIDATION OF CYSTEINE ON GLASSY-CARBON ELECTRODES, Electroanalysis, 9(16), 1997, pp. 1257-1261
Glassy carbon electrodes (GCE's) modified with phthalocyanine complexe
s of Rh, Ru and Os are employed for the catalytic oxidation of cystein
e. When cyanide and dimethylsulfoxide (DMSO) are used as axial ligands
giving (DMSO)(Cl)(RhPc)-Pc-III, [(CN)(2)(RhPc)-Pc-III](-), (DMSO)(2)O
sPcII, and [(DMSO)(2)Ru(II)Pc]. 2DMSO complexes, the peak currents for
the oxidation of cysteine increase after each scan, indicating an inc
rease in the catalytic activity of the electrode with repetitive scann
ing. This improvement in the catalytic activity of the GCE after the f
irst scan is attributed to the formation of dimeric pi cation radical
species at the electrode surface.