Synthesis and structure of trinuclear pyrazolate-bridged acetates M3(μ-dmpz)4(Hdmpz)2(OOCMe)2 (M = Zn or Co; Hdmpz = 3,5-dimethylpyrazole)

We discovered that reactions of hydrous cobalt and zinc acetates with 3,5-dimethylpyrazole (Hdmpz) in boiling xylene or toluene or upon the thermolysis of solid precursors (150°C) yield trinuclear pyrazolate-bridged complexes M3 (μ-dmpz)4(Hdmpz)2 (OOCMe)2(M = Zn or Co). Depending on the crystallization conditions, these complexes contain various solvating molecules (benzene, toluene, or Hdmpz), which influences the character of intramolecular and intermolecular hydrogen bonding, as shown by X-ray crystallography.