A numerical modelling of voltammetric reduction of substituted iodobenzenes reaction series. A relationship between reductions in the consecutive-mode multistep system and a multicomponent system. Determination of the potential variation of the elementary charge transfer coefficient.
The cyclic voltammetry reduction process of the reaction series of substituted iodobenzenes X-C6H4-I where X = H, p-Cl, p-Br, p-I, p-CH3, m-CF3 was investigated in 0.3 M TBAP in DMF. A numerical model of the process consistent with the ECE mechanism of mono-iodobenzenes reduction and consecutive ECE-ECE reduction of p-diiodobenzene was applied. On the basis of alpha(i) vs. E(p,i) dependence, the value of delta a(i)/delta E was found to be 0.37 +/- 0.07 for first electron transfer (Eq. (10)). The ECE-ECE system seems to be an another example of elementary alpha kinetic discrimination between two identical two-electron processes analogous to that described in a previous paper (Sanecki, P., Kaczmarski, K. (1999). J. Electroanal. Chem. 471, 14 and erratum to it (2001)). A method of simultaneous treatment of the substrate and all electroactive intermediates, i.e. the transformation of any experimental consecutive CV reduction curves (e.g. ECE or ECE-ECE) into curves corresponding to reduction of the multi-component systems is presented and discussed.
Sanecki
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P
Faculty of Chemistry, Rzeszów University of Technology, Poland. psanecki@prz.rzeszow.pl