A Study on Solid State Thermal Decomposition Characteristics of Some Metallo-Organic Compounds. Part-II. Thermal Dehydration and Decomposition Characteristics of Some Hydrated Metal Malonates

Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, Calcutta-700 032

Manuscript received 2 June 1982, revised 4 April 1984, accepted 20 September 1984

Solid state dehydration of the hydrated, Ca, Mn, Co, Ni, Cu and Zn salts of malonic acid and subsequent decarboxylation of the anhydrous salts have been studied by simulta-neous DTA, TG and DTG techniques. The thermal stability order of the hydrates has been found to be Ni(mal), 2.5H₂O>Co(mai).2H₂O>Mn(mai).2H₂O>Zn(mai).2H₂O> Ca(mal).2H₂O>Cu(mal).2H₂O. But in the decarboxylation process the trend observed is Ca(mal)>Ni(mal)>Co( mal)>Mn(mal)>Zn(mal)>Cu(mal). Thermal parameters like activation energy, enthalpy change and order or reaction for each process have been com-puted by standard methods.