Synthesis and Oxidative Stability of an Anionic Perfluoroethyl Cobalt(III) Complex

Upon reaction of the versatile tris(perfluoroethyl) cobalt(III) precursor [ fac ‐(MeCN) 3 Co(C 2 F 5 ) 3 ] with potassium tris(pyrazolyl)borate (KTp) in the presence of a tetraphenylphosphonium salt, κ 2 ‐ and κ 3 ‐ adducts of the scorpionate ligand with cobalt were observed. Heating this mixture to 50 °C induced complete κ 3 ‐coordination of the Tp ligand to cobalt to afford the anionic complex [PPh 4 ][( κ 3 ‐Tp)Co(C 2 F 5 ) 3 ] in 81 % yield. This new fluoroalkyl cobalt complex was characterized by NMR and UV‐Vis spectroscopies, X‐ray crystallography, and cyclic voltammetry. The oxidation of [PPh 4 ][( κ 3 ‐Tp)Co(C 2 F 5 ) 3 ] occurs at much less‐positive potentials relative to the related [(MeCN) 3 Co(C 2 F 5 ) 3 ] and [(tpy)Co(C 2 F 5 ) 3 ] derivatives.