THERMAL-BEHAVIOR OF SULFATO AND NITRATO COMPLEXES OF CERIUM(IV)

Four sulphato and nitrato complexes of cerium(IV), viz. (NH4)4Ce(SO4)4 .2H2O (1), (NH4)2Ce(SO4)3 (2), (NH4)2Ce(NO3)6 (3) and Cs2Ce(NO3)6 (4) were studied by simultaneous TG/DTA under various experimental conditi ons in order to establish their decomposition mechanism and to compare the results with the literature data which have been reviewed. In the case of the ammonium compounds (1, 2 and 3) the decompositions are ac companied by changes in the oxidation state of cerium; the presence of Ce(III) and Ce(IV) were studied by ex situ magnetic susceptibility an d XPS measurements. The crystal structure of (1) was determined as wel l. It forms monoclinic crystals with space group P2(1)/c; the paramete rs of the unit cell are: a = 12.638(18) angstrom, b = 11.362(10) angst rom, c = 13.607(11) angstrom, beta = 110.17(9)-degrees, V = 1834.05 an gstrom-3.