Cooperativity‐Driven Reactivity of a Dinuclear Copper Dimethylglyoxime Complex

Abstract

AbstractIn this report, we present the dinuclear copper(II) dimethylglyoxime (H2dmg) complex [Cu2(H2dmg)(Hdmg)(dmg)]+(1), which, in contrast to its mononuclear analogue [Cu(Hdmg)2] (2), is subject to a cooperativity‐driven hydrolysis. The combined Lewis acidity of both copper centers increases the electrophilicity of the carbon atom in the bridgingμ2‐O−N=C‐group of H2dmg and thus, facilitates the nucleophilic attack of H2O. This hydrolysis yields butane‐2,3‐dione monoxime (3) and NH2OH that, depending on the solvent, is then either oxidized or reduced. In ethanol, NH2OH is reduced to NH4+, yielding acetaldehyde as the oxidation product. In contrast, in CH3CN, NH2OH is oxidized by CuIIto form N2O and [Cu(CH3CN)4]+. Herein are presented the combined synthetic, theoretical, spectroscopic and spectrometric methods that indicate and establish the reaction pathway of this solvent‐dependent reaction.