Insights into the Coordination and Extraction of Yttrium(III) Ions with a Phenoxyacetic Acid Ionic‐Liquid Extractant

Abstract

Phenoxyacetic acid type extractants such as sec‐octylphenoxyacetic acid (CA‐12), sec‐nonylphenoxyacetic acid (CA‐100), and the resulting bifunctional ionic‐liquid extractants were developed to separate yttrium from heavy rare‐earth elements (REEs). To obtain information on the coordination chemistry of this type of bifunctional ionic‐liquid extractant, the CA‐12 analogue n‐octylphenoxyacetic acid (HOCTPOA) was synthesized, and its structure was characterized by single‐crystal X‐ray diffraction analysis. Then, a bifunctional ionic‐liquid extractant based on HOCTPOA, namely, [N1888][OCTPOA] (N1888 is methyltrioctylammonium) was synthesized. The study of the extraction of yttrium with [N1888][OCTPOA] in chloride media was conducted by IR spectroscopy, log D versus log C slope analysis, ESI‐MS, extended X‐ray absorption fine structure (EXAFS), and DFT studies. The EXAFS data indicate that a YIII extraction complex with phenoxyacetic acid formed. Three possible YIII coordination cations were calculated by the DFT method, and the obtained Y–O bond lengths were comparable to the results from EXAFS fitting. A possible structure for the overall extracted complex was proposed, and this knowledge should contribute to a better understanding of the extraction process with phenoxyacetate‐type bifunctional ionic liquids.

Binary Pectin-Chitosan Composites for the Uptake of Lanthanum and Yttrium Species in Aqueous Media

“…For example, activated PAN/CNS-70 NFMs used carbon nanospheres with large surface areas to support dense levels of carboxyl groups for high uptake of La 3+ [34]. Similarly, PAA-grafted adsorbents also showed high La 3+ uptake capacity [35,36]. A key difference between PAA and pectinbased biopolymers is the much higher density of -COOH groups in the case of PAA (ca.…”

Effective removal of calcium and magnesium sulfates from wastewater in the rare earth industry

“…26 Recently, mono-substituted alkylphenoxy acetic acid derivatives (POAAs) were reported. [27][28][29] The former can be used for the separation of high-purity yttrium from RE mixture, 30 whereas the latter plays an important role in the enrichment and transformation of RE elements. 31,32 To the authors' knowledge, the coordination characteristics of Ca and Mg ions with carboxyl groups are similar to those of RE ions.…”

Crystal structure of catena-poly[diaqua-bis(μ2-2-(4-(2,4,4-trimethylpentan-2-yl)phenoxy)propanoato-κ2 O:O')-(2-(4-(2,4,4-trimethylpentan-2-yl)phenoxy)propanoato-κ2 O,O')yttrium(III)], C51H79O11Y

“…Various extractants have been developed for extraction and separation of rare earths, among organic acid proved to be efficient extractants. In our present project [5,6], the para-(tert-octylphenoxy)iso-propanoic acid was used for the extraction of yttrium ions.…”