Dependence of mechanisms to thermodynamics in the electrochemical study of different electrophiles in the presence of some sulfur nucleophiles

Electrochemical study of different electrophiles in the presence of p-toluenesulfinic acid and 2-mercaptobenzothiazole as sulfur nucleophiles was investigated. Mechanistic study of the electrochemical reactions indicates that the electrochemical oxidation of some species in the presence of the sulfur groups has different mechanisms, but some other species in the presence of both sulfur nucleophiles have the same mechanism. To explain the reason for this difference, the computational study was used. Thermodynamic investigation shows that when ∆G_tot of the electrochemical oxidation of products are less than that of initial species, the electrochemically produced species can be oxidized during controlled-potential coulometry. The results of this work indicate that the computational study can be used to justify the reaction mechanisms. Cyclic voltammetry, linear sweep voltammetry, and controlled-potential coulometry were used to obtain the experimental results. Also, by the use of BP86 level of theory and 6–31 + G(d,p) basis set, the theoretical data were obtained. Graphic abstract: