A H-Bonding and Electrostatic Interaction Combined Strategy for TcO₄^– Separation by a Nitrotriacetate-Derived Amine–Amide Extractant

Abstract

Effective and selective separation of technetium from acidic nuclear liquid waste is highly desirable for partitioning and transmutation but is of significant challenge. Highly efficient extraction of pertechnetate can be achieved by taking H-bonding and electrostatic interaction combined strategy. Base on this strategy, an amine−amide ligand NTAamide(n-Oct) was employed to extract TcO 4 − in HNO 3 solution. Using n-dodecane as a diluent, NTAamide(n-Oct) demonstrated excellent extractability and good selectivity toward TcO 4 − with a rapid extraction equilibrium that could be reached in less than 1 min. Its maximal loading capacity for TcO 4 − was almost 100 times as much as that of traditional amine extractant Aliquat-336 nitrate. Meanwhile, TcO 4 − could be efficiently stripped from the loaded organic phase by (NH 4 ) 2 CO 3 solution. Slope analysis indicated the formation of a 1:1 complex of NTAamide(n-Oct) with TcO 4− . The extraction conformed to the anion exchange extraction model, as confirmed by analyses of single-crystal X-ray diffraction, 1 H NMR titration, FTIR, and ESI-MS.

Extraction and Complexation Investigation of Palladium(II) by a Nitrilotriacetate-Derived Triamide Ligand

“…In recent years, a new nitrilotriacetate-derived triamide N-donor ligand (referred to as NTAamide) with a central N atom surrounded by three amide units has been attracting more and more attention of researchers. − Sasaki et al first reported the extraction ability of n -octyl-substituted NTAamide­( n -Oct) toward 73 metal ions from the HNO 3 medium . It was observed that the D Pd value could reach the magnitude of 1 × 10 4 during the extraction of Pd 2+ in a 0.20 mol/L HNO 3 solution with 0.01 mol/L NTAamide­( n -Oct) in n -dodecane.…”

Complexation of a Nitrilotriacetate-Derived Triamide Ligand with Trivalent Lanthanides: A Thermodynamic and Crystallographic Study

“…First, excessive lanthanide oxide Ln 2 O 3 was dissolved in 1.0 mol/L HClO 4 solution; then, the remaining filtrate was removed and dried in air to obtain solid Ln­(ClO 4 ) 3 . N , N , N ′, N ′, N ″, N ″-hexaethylnitrilotriacetamide NTAamide­(Et) was synthesized by referring to the previous literature, and the corresponding characterization data are summarized in the Supporting Information.…”

A Novel Functionalized Ionic Liquid for Highly Selective Extraction of TcO4–

“…Solvent extraction is another efficient approach for the separation and removal of TcO 4 – and ReO 4 – from aqueous media. The commonly used extractants include amine extractants, − amine–amide ligand, , and cationic agents such as tetraorgano-ammonium and tetraorgano-phosphonium . By forming a hydrophobic ion pair between the positively charged extractant and TcO 4 – via electrostatic interaction, technetium is transferred from the aqueous phase into the organic phase.…”

“…According to our previous research , and the prior literature, , we found that the compounds containing imidazolium have strong affinity to TcO 4 – . It was reported in the literature that diamide compounds also have relatively high affinity for TcO 4 – . , In order to obtain a better extractant for TcO 4 – , we combined these two functional groups and synthesized a new ionic liquid MIMDIDOA. Its structure was characterized by proton nuclear magnetic resonance ( 1 HNMR), infrared spectroscopy­(IR), electrospray ionization mass spectrometry­(ESI-MS), energy-dispersive spectrometry (EDS), and X-ray photoelectron spectroscopy (XPS).…”