The electrochemistry of organic compounds in the 20th century is built on the work done in the 19th century. The invention of the battery, the Volta pile, in 1800,1 was essential for the development of electrolysis as such experiments require a current running during an extended period. Volta, however, did not regard the chemical reactions observed at the electrodes as essential for the function of the battery and his position in science was so high that no preparative electrolyses were made until Faradays experiments in the eighteen thirties. Faraday was the first who made an electroorganic synthesis2 by electrolyzing an acetate solution and obtaining a gaseous product, ethane. The anodic oxidation of salts of fatty acids to hydrocarbons with loss of carbon dioxide was developed by Kolbe3 to become the first useful electroorganic synthesis, and it was later in the century extended by Brown and Walker4 to electrolysis of salts of monoesters of dibasic acids resulting in dimerization to esters of dibasic acids. The first electrochemical reduction of an organic compound seems to be the reductive dehalogenation of trichloromethanesulfonic acid to methanesulfonic acid5 at a zinc electrode. During the second half of the 19th century preparative organic electrochemistry bloomed and a very optimistic view on the synthetic possibilities of the new method both for laboratory and technical applications was expressed. In this classical period several oxidations and oxidative substitutions as well as reductions of nitro compounds, carbonyl derivatives and dehalogenation reactions were performed; however, in most cases mixtures of products were obtained. Many of these investigations were made by the groups of Elbs, Gattermann, Haber, Lob, and Tafel. Their publications appeared mostly in Ber. Dtsch. Chem. Ges., Z. Elektrochemie, and J. Prakt. Chem. In 1898 Haber6 published a classical paper on the stepwise reduction of nitro compounds; in this he realized that by using a constant current density the effective reduction potential would gradually become more negative and that it was essential for a selective reaction to keep the potential at the working electrode constant. However, control of the potential could only be made manually and there was no easy way to find the optimal potential for a given reaction.
Mendeley saves you time finding and organizing research
Choose a citation style from the tabs below