Synthesis of functionalised BTPhen derivatives – effects on solubility and americium extraction

Abstract

Separation of the minor actinides (Am/Cm) from spent nuclear fuel post-PUREX process is expected to play a key part in new reprocessing methodologies. To date, a number of selective americium extractants from the BTPhen ligand family have been identified. In this investigation, we synthesise 24 novel BTPhens with additional functionality to determine the effects on solubilities and americium extraction capabilities. The data obtained will allow for tuning of steric/electronic properties of BTPhens in order to assist future extractant design.

Screening of the Structure of Americium Extractants Based on a 2,2’‐Bipyridyl Scaffold: a Simple Way to a N2,O2‐Tetradentate Ligands Library for Rational Design of An/Ln Extractants

“…This is in agreement with the high influence of the spatial character of the substituents for the BTBP‐type and BTPhen‐type compounds on their solubility and metal distribution coefficients. Therefore the proper balance should be found between the effectiveness of the separation and the selectivity: thus the alkyl groups look like the better choice compared with the electron donating alkoxy groups.…”

“…One can expect that the substituents which enhance the disorder of the system (asymmetrically substituted bipyridine or the meta ‐substituted aromatic rings) will increase the metal recovery to a greater extent than others. This result is significantly differing from the structure‐properties relations found for triazine‐type extractants seems due to “hard” nature of the amidic oxygen atom.…”

“…The distribution coefficients demonstrate a tenfold rise when going from N ‐ethylanilide to N‐ethyl‐ p‐ alkylanilides of 2,2’‐bipyridine‐6,6’‐dicarboxylic acid . The effect on metal affinity of a substituent in the pyridine ring was studied for 6,6’‐bis(1,2,4‐triazin‐3‐yl)‐2,2’‐bipyridine‐type (BTBP) and 2,9‐bis(1,2,4‐triazin‐3‐yl)‐phenanthroline‐type (BTPhen) compounds, but not for heterocyclic diamides. Moreover, the BTP‐type ligands show increase in both the americium distribution and Am/Eu selectivity with the aliphatic side chain elongation for tetrachloroethylene and dodecane solvents and the opposite dependence for the ionic liquids solvents .…”

Exploring the Subtle Effect of Aliphatic Ring Size on Minor Actinide‐Extraction Properties and Metal Ion Speciation in Bis‐1,2,4‐Triazine Ligands

“…However,t here has been less emphasis on modifying the aliphatic rings appended to the triazine rings of ligands 1-3. [12] We wished to determinew hat effect changing the aliphatic ring size would have on the actinide extraction properties and metal speciationo ft hese ligands. In this paper, we report our studies on novel bis-1,2,4-triazine ligands con- taining af ive-membered aliphatic ring appended to the outer triazine rings insteado fasix-membered ring (as in 1-3), and we show that this small but subtle modification to the ligand structurec an have unexpected effects on the extraction properties and metal ion speciation of these ligands.…”

Extraction of minor actinides, lanthanides and other fission products by silica-immobilized BTBP/BTPhen ligands

“…1,2 One approach currently being studied for the long-term management of irradiated fuel is to separate these minor actinides from the lanthanides; after which they can be transmuted, using high-energy neutrons or fast neutrons in a Generation IV reactor, to short-lived radionuclides or stable non-radioactive elements. [3][4][5][6][7][8][9] Separation of the minor actinides from the chemically similar lanthanides has been achieved by the SANEX solvent extraction process (Selective ActiNide EXtraction) using soft N-donor ligands containing the 1,2,4-triazine moiety (Fig. 1).…”