Abstrait

Electrochemical Reductive Dehalogenation of Brominated Organic Compounds in Watermethanol Media on a Boron Doped Diamond Electrode: Bulk Electrolysis

S. M. Kulikov and K. M. Juettner

Electrochemical reduction of 1, 2-dibromoethane, bromoethane and bromobenzene on the Boron-Doped Diamond Electrode (BDDE) was studied in aqueous methanol media. The reaction was carried out at room temperature in the potential region between - 1.5 V and - 2.1 V. The removal of the first bromine from 1, 2-dibromoethane goes smoothly and fast at - 1.5 V; current efficiency is close to 100% in the beginning of the reaction, and even at 90% conversion is almost 60%. The removal of the second (and last) bromine is slower; it takes about 50 hr at - 1.7 V to reach 90% conversion, with current efficiency of about 5%. Bromine can be removed from bromobenzene by electrochemical reduction at potentials more negative than -1.8V. However, even at - 2.1V, the rate constant is small and the estimated current efficiency is less than 1%.