Catalytic Processes Involving Nickel-Containing Complexes

Square-planar complexes have been investigated as catalysts for the reduction of carbon–halogen bonds in alkyl halides.(1,2) Specifically, electrogenerated [[2,2´-[1,2-ethanediylbis(nitrilomethylidyne)]bis[phenolato]]-N,N´,O,O´]nickelate(I), nickel(I) salen, has seen use as a catalyst, both in a homogeneous phase and as a polymer coating on an electrode surface, for the reduction of carbon–halogen bonds.(3–11) Along with the cobalt analogues of the nickel-containing complexes, electrogenerated salen-type catalysts have long been studied in the Peters group.(3–6) Most research has centered on the application of electrogenerated low-valent nickel- and cobalt-containing complexes as mediators for the reduction of halogenated species. Focus has been given to the reduction of carbon–halogen bonds, whereas useful chemistry such as the formation of aldehydes, ketones, and cyclic products is performed.(3–5)

We have begun to evaluate how different substituents on the imino carbons affect the electrochemical properties of the newly formed species. Findings from electroanalytical experiments (cyclic voltammetry and controlled-potential electrolysis) will be discussed.

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