Tetraethylammonium -toluenesulfonate supporting electrolyte

Some typical results are shown in Table 2. The table shows that oxidation of conjugated dienes such as isoprene, piperylene (1,3-pentadiene), cyclopentadiene and 1,3-cyclohexadiene with a carbon anode in methanol or in acetic acid containing tetraethylammonium p-toluenesulfonate (EtjNOTs) as the supporting electrolyte yields mainly 1,4-addition products2. 1,3-Cyclooctadiene yields a considerable amount of the allylically substituted product. 

The anodic oxidation of 1,2-diols and their ether derivatives is a simple and clean method for the fission of glycols to the corresponding carbonyl compounds (equation 1). The reaction is carried out using carbon electrodes in methanol containing tetraethylammonium p-toluenesulfonate as a supporting electrolyte. ... 

Although the electrochemical coupling to form ADN had been known since the 1940s, the breakthrough came only when Baizer found out that the use of quaternary ammonium salts such as tetraethylammonium /7-toluenesulfonate as supporting electrolytes led to mass yields of 90% of ADN [75]. Following Baizer s discovery, an intensive process development effort was undertaken at Monsanto s Technical Centre in Pensacola, Florida [76]. 

Table 5. Dissociation constants (—log Kg = pKo) of 1 1 complexes of anionic guests with host 24 in water at 298 K (supporting electrolyte 0.1 M sodium- or tetraethylammonium toluenesulfonate, methods A = pot itiometry, B = pH titraticm, C = photometry)" ...

Careful selection of the supporting electrolyte is a key point in the hydrodimerization process. Monsanto has chosen tetraethylammonium p-toluenesulfonate for their solution process. In concentrations of from 20% to 40%, it increases the solubility of acrylonitrile in the anolyte and retards the formation of byproduct. Asahi Chemical uses less hydrophobic supporting electrolyte, in concentrations of about 10%, for their emulsion process. Thus, adiponitrile formed in the emulsion process is separated from the reaction mixture by physically breaking down the emulsion and then separating the oil layer. The loss of supporting electrolyte and the electric power consumption are lower in the emulsion process than in the solution process. 

---