engleski

Anodic Behaviour of Some Bispyridinium Oximes on a Glassy-Carbon Electrode

The electrochemical oxidation of selected bispyridinium oximes, including conventional oximes HI-6 [(1-(((4-carbamoylpyridinium-1- yl)methoxy)methyl)-2-((hydroxyimino)- methyl)pyridinium chloride] and TMB-4 [N, N'- (propano)bis(4-hydroxyiminomethyl)pyridinium bromide], as well as a new generation oxime K048 [1-(4-hydroxyiminomethylpyridinium)-4-(4- carbamoylpyridinium) butane dibromide], was studied at a glassy-carbon electrode over a wide range of experimental conditions, using cyclic and square-wave voltammetry. It was observed that in all investigated compounds the oxidation of oxime moiety (the first oxidation peak) occurs. This process is diffusion controlled, pH dependent, and occurs in a complex ECE mechanism. The monoximes HI-6 and K048 exhibited only one anodic peak, while TMB- 4 undergoes two consecutive oxidation reactions due to the presence of two oxidizable oxime moieties. The final product of electro- oxidation of oxime moiety, hydroxy-nitroso intermediate, undergoes further oxidation at more positive potential.

bispyridinium oximes; HI - 6; K048; TMB - 4; cyclic voltammetry; square - wave voltammetry; electrochemical oxidation

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