Progress in the Chemistry of Actinide Elements

Abstract

For the last years the investigations in the field of actinide chemistry are carried out in the following main directions: Application of microchemical methods for synthesis of compounds of actinide elements from americium to einsteinium, development and application of the microchemical methods for identification of the oxidation state of microelement compounds and determinatio of their physicochemical constants, macrochemical synthesis of simple and complex compounds of near actinides, improvement of separation processes of transuranium elements. In this connection the increased interest to the synthesis of the volatile compounds of actinide elements must be emphasized. Comparing the properties of the elements of actinide and lanthanide series we can speak about the anology of position of the elements of both series in mendeleev's periodic system. As to the chemical properties of 5f and 4f elements there are more distinctions than anology. High valency forms of main near actinides which is unknown for lanthanides exist mainly as oxygen compounds Now it is established that the ability of elements to form high oxidation states is decreased in actinide series from uranium to curium. Contrary to lanthanides the elements of the second part of the actinide series are characterized by the stabilization of low valency states increasing with z the 102 element having the most stable low valency state. So the ability of formation of compounds in high oxidation state is decreased in actinide series when z increases and the tendency to the stabilization of low valency forms is increased. These regularities are unknown in lanthanide series.