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Diffusion, Adsorption and Electrode Kinetics of Electro‐oxidatons on a Stationary Solid Electrode
Author(s) -
BozalPalabiyik Burcin,
Kurbanoglu Sevinc,
Uslu Bengi,
Ozkan Sibel A.,
Zuman Petr
Publication year - 2016
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.201600372
Subject(s) - chemistry , electrode , diffusion , dissociation (chemistry) , electrochemistry , piperazine , kinetics , limiting current , molecule , inorganic chemistry , analytical chemistry (journal) , thermodynamics , organic chemistry , physics , quantum mechanics
The i ‐ E oxidation curves, obtained using a boron doped diamond electrode, for studies of oxidations of two piperazine derivatives ARIP (I) and PIRI (II), resulted in a sharp increase of current in the range of the oxidation potentials. After reaching a value, depending on concentration of I or II, the current remains practically constant up to +1.6 V. Such limiting currents i 1 are a linear function of concentrations and depend on the v 1/2 . Hence it is diffusion controlled, shifts of the oxidation potentials indicate, that the monoprotonated forms are oxidized. At more negative potentials a limiting current i 2 occurs, due to the oxidation of the diprotonated form. Current i 2 increases with decreasing pH in a shape of a part of a dissociation curve. Diffusion control reflects the large size of molecules I and II. The two‐electron oxidations yield a C=N bond in the piperazine ring. It seems to be the first reported diffusion controlled oxidation curves obtained on a stationary solid electrode.