Cyclic voltammetry, controlled-potential (bulk) electrolysis, gas chromatography, gas chromatography-mass spectrometry, and high-performance liquid chromatography-electrospray ionization-mass spectrometry have been utilized to investigate the catalytic reduction of 4,4'-(2,2,2-trichloroethane-1,1-diyl)bis(chlorobenzene) (DDT) by nickel(1) salen electrogenerated at a carbon cathode in dimethylformamide (DMF) containing 0.050 M tetramethylammonium tetrafluoroborate (TMABF(4)). Cyclic voltammograms for reduction of nickel(II) salen in the presence of DDT provide evidence for catalytic reduction such as enhanced cathodic current for the nickel(II) salen-nickel(1) salen redox couple and a decrease in the anodic current associated with oxidation of nickel(1) salen. Bulk electrolysis of nickel(11) salen-DDT solutions at reticulated vitreous carbon cathodes leads to a mixture of products that includes 1,1-diphenylethene, 1-chloro-4-(1-phenylvinyl)benzene, 4,4'-(ethene-1,1-diyl)bis(chlorobenzene) (DDNU), 4,4'(2-chloroethene-1,1-diyl)bis(chlorobenzene) (DDMU), 4,4'-(2-chloroethane-1,1-diyl)bis(chlorobenzene) (DDMS), 4,4'-(2,2-dichloroethane-1,1-diyl)bis(chlorobenzene) (DOD), and 4,4'-(2,2-dichloroethene-1,1-diyl)bis(chlorobenzene) (DDE). In addition, we have detected adducts formed from a fragment of DMF and radical intermediates arising from reduction of DDT, along with nickel salen species for which the imino (C=N) bond of the ligand is modified with different intermediates derived from catalytic reduction of DDT. A mechanistic scheme is proposed to account for the formation of products. (C) 2013 Elsevier B.V. All rights reserved.