Experimental and theoretical studies on the extraction behavior of Cf(iii) by NTAamide(C8) ligand and the separation of Cf(iii)/Cm(iii)

Abstract

We performed basic chemical studies on Cf using NTAamide extractant. The results of experiments and DFT calculations show that NTAamide has a good coordination ability to Cf/Cm and is expected to be applied to Cf/Cm separation.

Understanding the Complexation of Alkyl-Substituted Nitrilotriacetamides with Uranium: A Study by Absorption Spectroscopy and Microcalorimetry

“…35,36 A few interesting reports are also available on the extraction of trivalent actinides and lanthanides with a series of NTAamides having a varying alkyl chain. 31,37,38 Very recently, the effect of the alkyl chain length of the NTAamide ligands on the Am/Eu selectivity has been addressed by thermodynamic and quantum theory calculations, which has shown that elongation of the alkyl chain can increase the selectivity of Am 3+ over Eu 3+ . 31 The main focus of the NTAamides, as discussed earlier, is the complexation and separation of trivalent actinides with less or no emphasis on understanding its complexation.…”

“…Theoretical calculations of the complex stabilization energy predicted that the DGA ligand preferably coordinates to the Eu 3+ ion when compared with Am 3+ , but NTAamide ligands selectively coordinate to the Am 3+ ion when compared with Eu 3+ . Our earlier studies have also shown the selective extraction of trivalent actinides over lanthanides due to binding of the “soft” actinide ion with the “soft” donor central N atom of the NTAamides. , A few interesting reports are also available on the extraction of trivalent actinides and lanthanides with a series of NTAamides having a varying alkyl chain. ,, Very recently, the effect of the alkyl chain length of the NTAamide ligands on the Am/Eu selectivity has been addressed by thermodynamic and quantum theory calculations, which has shown that elongation of the alkyl chain can increase the selectivity of Am 3+ over Eu 3+ …”

Sequestration of Np(IV) and Pu(IV) with Hexa-n-octyl nitrilotriacetamide (HONTA) in an Ionic Liquid: Unusual Species vis-à-vis a Molecular Diluent

“…Reports by Sasaki et al have suggested that tripodal amide ligands such as N,N,N′,N′,N″,N″ -hexa- n -octyl nitrilotriacetamide (HONTA) is one of the most efficient extractants for the extraction of actinide ions such as UO 2 2+ and Pu 4+ from nitric acid feeds . The authors have also reported selective extraction of trivalent actinides vis-à-vis the trivalent lanthanides due to binding of the “soft” actinide ion to the soft donor “ N ” atom making the ligand tetradentate. , Other research laboratories have also studied the extraction behavior of HONTA and its homologs with varying alkyl chains with some very interesting results. − Though Np is not considered important in the PUREX process, as it escapes to the raffinate stream, its chemistry needs to be understood when amide-based extractants are used for spent fuel reprocessing. In this context, one needs to study the extraction behavior of Np, mainly in its +4 oxidation state with HONTA as well.…”