The effects of altering alkyl substituents in trialkyl phosphates on the extraction of actinides

Abstract

The extraction of neptunium(IV), plutonium(VI), neptunium(IV) and plutonium(IV) nitrates by trialkyl phosphates follows the same general pattern as the extraction of uranyl nitrate when the alkyl groups are varied. However, the extraction of thorium nitrate is greatly depressed when bulky alkyl groups are introduced into the extractant molecule. This behaviour of thorium nitrate appears to be due to the fact that three extractant molecules are co-ordinated to each thorium atom in the prevalent mode of extraction. Only two molecules of extractant are required for the other actinides.