Synthesis of palladium(II) 3d-metal(II) paddlewheel acetate-bridged heterodimetallic complexes: Unexpected catalysis by water molecules

A study of the reaction kinetics between the trinuclear palladium(II) acetate Pd3(μ-OOCMe)6 (1) and the mononuclear 3d-metal (NiII, CoII, CuII) acetates in acetic acid under water-specified conditions revealed a fairly complicated reaction mechanism triggered by the primary hydrolytic cleavage of an acetate bridge in molecule 1. The isolated reaction products, as established by X-ray diffraction study, are 1D polymeric complexes {Pd(μ-OOCMe)4M(OH2)(HOOCMe)2}n (M = NiII, CoII, CuII, MnII, ZnII) built of the PdII-based paddlewheel units [Pd(μ-OOCMe)4M] and linked trough the H-bonded H2O and MeCOOH molecules.