Dimeric “paddle-wheel” cymantrenylcarboxylates of copper (II)

The interaction of cymantrenylcarboxylic acid (C5H4CO2H)Mn(CO)3 (CymCOOH) or its potassium salts with salts of Cu (II) in alcohol or water with subsequent treatment with ligands L gives binuclear complexes LCu(CymCOO)4CuL where L = THF (I), Et2O (II), CymCOOH (III) or PPh3 (IV). The structures of I–III were solved by X-ray analyses. The frame of all complexes is constructed as “paddle-wheel” with four carboxylate bridges. At thermal decomposition of I and II in Ar the loss of L ligands took place, then the decarboxylation of all CymCOO groups was observed followed by decarbonylation with elimination of nine CO groups only. Finally the loss of cyclopentadienyl ligands results the solid product which according to powder XRD data contains metallic copper and Mn1.5Cu1.5O4 phase probably due to the splitting of the retaining CO groups.