AbstractIt was found that the reaction of 1,2‐dicyano‐1,2‐ethenedithiolate, resp. of bis(1,2‐dicyano‐1,2‐ethenedithiolato)cuprate(2‐), with Cu2+does not lead to copper bis(1,2‐dicyano‐1,2‐ethenedithiolato)cuprate(2‐) dihydrate (1a) as described in the literature but to a reaction product which has a complex structure containing mainly Cu+. This compound as well as complexes with the same ligand, but with Cu+, Cu2+or Cu3+as the central atom, were synthesized and tested with and without added cuprous chloride as catalysts for the oxidative polymerization of 2,6‐dimethylphenol. Included in this investigation were some copper complexes with the isomeric ligand 2,2‐dic