Polarographische Untersuchungen an verschieden substituierten Sulfoximiden

S,S-Disubstituted sulfoximides are normally reduced in aqueous solutions by cleavage of a C-S bond. If the sulphur atom is part of a ring (e.g. benzothiophenesulfoximide), the corresponding cyclic sulfide will be formed. Sulfoximides are adsorbed at the DME. The half-wave potential is largely dependent on the concentration, the ionic strength and the presence of surface active agents. The function E_1/2=f(pH) results in the case of the N-alkyl-S,S-diarylsulfoximides in a curve with decreasing gradients at extreme pH values and in a straight line over the whole pH range in the case of the N-diethylaminoethyl-S,S-diaryl-sulfoximides. There is a linear correlation between the half-wave potentials and the Hammett σ-values of the S,S-diarylsulfoximides. The limiting current of the N-alkyl- and the N-unsubstituted sulfoximides decreases with increasing pH, the plot of i₁ against pH resembles a dissociation curve. N-Diethylaminoethylsulfoximides show characteristic deviations from this behavior, resulting from the strong pH dependence of the half-wave potential of N-diethylaminoethyl-benzenesulfinamide, which is formed as an intermediate.