Mossbauer study on thermal decomposition of ammonium tris(malonato)ferrate(III) tetrahydrate

Thermal decomposition of ammonium tris(malonato)ferrate(III) tetrahydrate, i.e. (NH4)(3)[Fe(CH2C2O4)(3)]. 4H(2)O has been studied up to 973 K in static air atmosphere employing Mossbauer and infrared spectroscopies, and non-isothermal techniques (TG, DTG, DTA). The anhydrous complex decomposes into an iron(II) intermediate at 453 K. The iron(II) species on further heating is reoxidized to alpha-Fe2O3 as the final thermolysis product. An increase in particle size of alpha-Fe2O3 with increasing decomposition temperature has been observed. The results are compared with the analogous oxalate complex.