ON THE EXISTENCE OF GADOLINIUM(III)-SULFITE DIHYDRATE GD2(SO3)3.2H2O

Different hydrates of Gd2(SO3)3 are obtained depending on preparation conditions. For preparation of Gd2(SO3)3, gaseous SO2 is passed through a suspension of Gd2O3 in H2O at room temperature until a clear solution is formed. Upon immediate heating to about 100-degrees-C a mixture of Gd2(SO3)3.2H2O and Gd2(SO3)3.3 H2O is formed. If the boiling procedure is performed after 6 days, a pure product consisting of the trihydrate is obtained. The different phases are identified by REM, DTA-TG-investigation and X-ray powder analysis. The X-ray powder pattern of Gd2(SO3)3.2H2O is consistent with patterns of isotype Ln2(SO3)3.2H2O were Ln = Pr, Nd, Sm and Eu.