Preparation and thermal reactivity of some rare earth and uranyl hydrazinesulfinates and sulfite hydrazinates

Hydrazinesulfinate and sulfite hydrazinate derivatives of rare earth elements of composition Ln(N2H3SOO)3(H2O) and Ln2(SO3)3(N2H4)x(H2O)y, respectively, where Ln=La, Ce, Pr, Nd and Sm, have been prepared and characterized by chemical analysis and infrared spectra. The uranyl complexes of the composition UO2(N2H3SOO)2, UO2(N2H3SOO)2(N2H4) and UO2SO3(N2H4)(H2O) have also been prepared under different reaction conditions and studied by different physicochemical techniques. Thermal properties of all these complexes have been studied by thermogravimetry, and differential scanning calorimetry. The hydrazinesulfinate derivatives of rare earth elements undergo thermal decomposition in multisteps to give the respective metal sulfate as the residue. The other series of complexes, viz., rare earth sulfite hydrazinates gave a mixture of metal sulfate and metal oxide as the end products. However, all the uranyl complexes undergo decomposition in air to give UO2SO3 as the final product.