Catalytic Reduction of 4,4′-(2,2,2-Trichloroethane-1,1- diyl)bis(chlorobenzene) (DDT) with Nickel(I) Salen Electrogenerated at Carbon Cathodes

(chlorobenzene) (DDT) was introduced as a pesticide; within only a few years, it became the most widely used insecticide in the world. By the mid 1970s, however, the Stockholm Convention prohibited the use of this compound throughout the United States due to the discovery that DDT and its degradation products have adverse effects on human health and the environment. 1,2 Although its global use is severely restricted, DDT is still persistent in the environment, and a strategy for its effective remediation is needed. Research that focuses on the catalytic electrochemical dechlorination of DDT and its reduction products is therefore of interest. In previous work in our laboratory, the direct and cobalt(I) salen-catalyzed reduction of DDT was investigated; it has been determined that 4,4′-(ethene-1,1-diyl)bis(chlorobenzene) (DDNU) and 4,4′-(2-chloroethene-1,1-diyl)bis(chloro-benzene) (DDMU) are the principal products. 2,3 Up to the present time, no work has been conducted that deals with nickel(I) salen-catalyzed reduction of DDT. Unlike cobalt(II) salen, nickel(II) salen is not air-sensitive, so it can be utilized to effect the reduction under simpler experimental conditions