Characteristic Features of Fixation of Ammonia by Copper(II), Nickel(II), and Cobalt(II) Ions in Pivalates

The reaction of adduct Cu2(OOCBut)4(thf)2 with polynuclear nickel(II) pivalate (prepared from NiCl2, HOOCBut, and KOH) or cobalt(II) pivalate (prepared by thermolysis of Co(II) acetate with excess acid at 160°C) in THF with a large excess of aqueous ammonia at room temperature leads to the formation of the mononuclear molecular complex Cu(OOCBut)2(NH3)2, the ionic complex [Ni(NH3)6](OOCBut)2, and unusual mixed-valence trinuclear complex {CoII(OOCBut)2(NH3)2[(µ-OH)CoIII(NH3)5]2}(OOCBut)4(H2O)2. The products were investigated by chemical analysis, X-ray diffraction, and IR spectroscopy.