Electro-oxidation of Catechol in the Presence of L-Histidine at Different pH

The electro-oxidation of catechol in presence of l-histidine has been investigated in aqueous solution with various ph values, different electrodes and different concentration of l-histidine by using cyclic voltammetry, differential pulse voltammetry and controlled potential coulometry. electrochemically generated o-benzoquinone (michael acceptor) from oxidation of catechol reacts with lower concentration of l-histidine as nucleophiles in the second scan of potential. the products obtained from the reaction are assumed to be 2-((3,4- dioxocyclohexa-1,5-dien-1-yl)amino)-3-(1h-imidazol-4-yl)propanoic acid that undergo electron transfer at more negative potentials than the catechol. the effect of ph of catechol in presence of l-histidine has been studied by varying ph from 5 to 11. the concentration effect of l-histidine with the fixed concentration of catechol (2 mm) was measured from 2 mm to 100 mm. the reaction was strongly influenced by the ph as well as concentration of l-histidine. the reaction is mostly favorable in 30 mm of l-histidine and 2 mm of catechol at ph 7. the behavior of the reaction mechanism was of ece type.