Numerical Modeling of ECE-ECE and parallel EE-EE mechanisms in cyclic voltammetry. Reduction of 1,4-benzenedisulfonyl difluoride and 1,4-naphthalenedisulfonyl difluoride

A numerical model of the process where the ECE-ECE sequence competes with the parallel EE-EE mechanisms of reduction has been developed. The ECE-ECE/EE-EE model was applied to complex, experimentally observed processes, in which the parallel path of anion-radical reduction could be expected. The applicability of the proposed model was examined experimentally for two chemical systems: (i) 1,4-benzenedisulfonyl difluoride (1,4-BDF) and (ii) 1,4-naphthalenedisulfonyl difluoride (.1,4-NDF). For both model compounds the reduction processes on Hg and glassy carbon electrodes were investigated by means of cyclic voltammetry performed in DMF solutions containing 0.3 M of TBAP. In contrast to other reductive cleavage reactions such as the fragmentation of the C-Hal-type bond, the electro-reduction of anion-radicals ArSO2F-. was evident. The elementary kinetic parameters of the process are determined and discussed.