Carbamoylphosphine oxide

CMPO. CMPO, or octyl(phenyl)-A,A-diisobutylcarbamoylmethylphosphine oxide (see Figure 26), was developed by Horwitz and co-workers as an efficient actinide extractant for use in the TRUEX process in the remediation of acidic nuclear waste solutions. Derivatives of carbamoylphosphine oxides (CMPO) have been studied in nuclear fuel processing schemes involved in transmutation concepts." ... 

Actinide species like U (VI), Pu (TV) and Am (HI) can be selectively sequestered with SAMMS that are decorated with carbamoylphosphine oxide (CMPO) analog ligands [11]. In this case, selectivity is excellent, with no conq)etition from the ubiquitous alkaline and alkaline earth cations, common transition metals or complexants like EDTA. 

The column medium is a polystyrene-divinylbenzene polymer with octylphenyl-N,N-diisobutyl carbamo-ylphosphine oxide extractant adsorbed on the hydrophobic polymer matrix. The carbamoylphosphine oxide functional group is an avid chelator for actinides in 0.16 M or higher concentration nitric acid, whereas alkali and alkaline earth metals are poorly bound. Lanthanides are only retained on the column at much higher nitric acid concentrations (>6 M). Therefore, even these are eliminated from the final matrix under the rinse conditions employed. A very hard base anion ligand is necessary to compete effectively with the carbamoylphosphine oxide ligands and elute actinides, including uranium, in a small volume. In Protocol 1, the fluoride ion from dilute hydrofluoric acid (HF) was chosen for this purpose. 

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