PREPARATION, SPECTROSCOPIC AND THERMAL STUDIES ON THE NEW SOLID COMPLEX CO2(NH2)2(H2O)2(SO4)2

The preparation and characterization is reported of the new solid bimolecular Co(III)-bridged sulphato complex Co2(NH2)2(H2O)2(SO4)2 formed by the reaction of urea with CoSO4.7H2O in aqueous media at 85-degrees-C. The infrared spectrum of the complex was recorded and the observed bands are assigned. Thermogravimetric (TG) and differential thermal analysis (DTA) measurements on the complex, and the infrared spectrum of the final decomposition product were also recorded. The data obtained agree quite well with the expected structure and show that the complex finally decomposes to form CoSO4. Detailed mechanisms for the complex formation and its thermal decomposition are given, together with the activation energy for each decomposition step.