Solvent Extraction of Trivalent Lanthanoid Ions with N,N'-Dimethyl-N,N'-Diphenyl-3-Oxapentanediamide

Abstract

The extraction of trivalent lanthanoid ions from nitric acid and hydrochloric acid solutions by -dimethyl-Af,Af-diphenyl-3-oxapentanediamide, DMDPhOPDA, was investigated. The distribution ratios in the nitric acid system were much higher than those in the hydrochloric acid system. In the nitric acid system, the dependencies of the distribution ratios on nitric acid and DMDPhOPDA concentrations showed a difference between lighter and heavier lanthanoid ions. The plots of the number of DMDPhOPDA molecules in the extracted species obtained from slope analysis in 4 mol dm"' nitric acid versus the ionic radius of trivalent lanthanoid ions exhibited a significant change around the middle of the lanthanoids (S-shape). The distribution ratios in the nitric acid system increased with an increase in the atomic number, while those in the HCl system decreased.

Separation of Rare Earth Elements from Base Metals in Concentrated HNO₃, H₂SO₄ and HCl Solutions with Diglycolamide

“…Besides these factors, the geometry of the coordination site in an extractant and the hydrophobicity of the extracted complex would also have an effect on the magnitude of E% value [5][6][7]; therefore, an additional study is required to further elucidate the mutual separation of Ln(III) with MODGA.…”

“…Among the f-elements, DGA shows high extractabilities for trivalent lanthanides (Ln(III)) [5][6][7] HCl and H 2 SO 4 solutions, respectively. MODGA was synthesized using a procedure similar to reference 8.…”

Efficient and Selective Acetylation of Biomolecules with 1-Acetylimidazole Catalyzed by Er(OTf)_3.

“…It is well known that rare earth ions have high affinity for hard donor atoms like ligands containing oxygen or hybrid oxygen-nitrogen atoms; [37] various research reported the extraction of lanthanides with the amides and their coordination with carbonyl group for the synthesis of ternary 4f-element complexes. [38][39][40] In addition, the formation of ligands obtained by bis-chelating mode of the pyrimidine carboxylate with lanthanides (III) is reported in crystallographic studies. [41] It can be supposed that the coordination with the carbonyl group of the pyrimidine base, assisted by an iminol keto tautomerism of cytidine that shifts the equilibrium toward the iminol tautomer in acid condition and high temperature, [42] favours the formation of 2-O-acetyl-cytidine in 45% yield (Figure 2).…”

Selective Acetylation of Small Biomolecules and Their Derivatives Catalyzed by Er(OTf)3

“…The 1 H-NMR spectrum of the product resulting from the acetylation of cytidine showed the formation of three isomers indicated as N-acetylcytidine (A) in 40%, acetylcytidine (C) in 45% and 5′-O-acetylcytidine (B) in 15% yields, respectively (Figure 1). It is well known that rare-earth ions have high affinity for hard donor atoms, such as ligands containing oxygen or hybrid oxygen-nitrogen atoms [52]; various researchers have reported the extraction of lanthanides with amides, and their coordination with carbonyl groups for the synthesis of ternary 4f-element complexes [53,54].…”

“…It can be supposed that the coordination with the carbonyl group of the pyrimidine base, assisted by an iminolketotautomerism of cytidine that shifts the equilibrium toward the iminol tautomer in acid conditions and at high temperatures [56], favours the formation of 2-O-acetyl-cytidine in 45% yield (Figure 2). It is well known that rare-earth ions have high affinity for hard donor atoms, such as ligands containing oxygen or hybrid oxygen-nitrogen atoms [52]; various researchers have reported the extraction of lanthanides with amides, and their coordination with carbonyl groups for the synthesis of ternary 4f-element complexes [53,54].…”