Sublimation Behavior of Actinoid Chelates of 2,2,6,6-Tetramethyl-3,5-heptanedione

Abstract Vacuum sublimation-recrystallizing temperatures were determined for a tracer amount of actinoid chelates of 2,2,6,6-tetramethyl-3,5-heptanedione in order to obtain information about their sublimation behavior. The influence of the amount of sample (in tracer scale or in milligram scale) on its sublimation-recrystallizing temperature was also examined. The sublimation-recrystallizing zone temperature of the tracer amount of chelate was lower than that of the milligram amount. In addition, the sublimation-recrystallizing zone temperatures of the actinoid chelates were found to be in the following sequence: UO22+>Am(III), Cm(III)>Th(IV), Np(IV), Pu(IV)>Cf(III). These results suggest that the sublimation technique can be applied to separate the actinoid elements in a carrier-free state.