An Ionophore for High Lithium Loading and Selective Capture from Brine

Abstract

The continuous demand and uneven dispersal of natural mineral resources of lithium with a low recycling rate of lithium commodities have forced researchers to look for alternative resources like geothermal brine, brackish brines, and sea brines. But selective lithium-ion extraction and even lithium-ion binding from these aqueous systems is a recognized challenge due to very high hydration energy and the coexistence of other like metal ions but appealing due to economic benefits. Therefore, the designed synthesis of synthetic ionophores with high lithium selectivity is crucial as they can work on dilute conditions without removal of interfering metal ions. However, most of the lithium selective ionophores known in the literature are mononucleated, and no emphasis is given on designing multinucleating ionophore systems to improve the lithium loading capacity which will open up unexplored paths toward the development of a more sustainable and economical extraction process. Herein, we describe a rare fluorogenic macrocyclic ionophore with two binding pockets for selective lithium recognition and extraction among various major alkali and alkaline earth metal ions of oceanic presence through both solid-state and solution studies. Under solid-liquid extraction conditions, this receptor shows a high lithium loading capacity of 135% with LiClO4 and 69.16% with LiCl salt with exclusive selectivity. Under liquid-liquid extraction conditions, this ionophore shows a loading capacity of 27% with 1 M LiCl and 48.57% with 1 M LiClO4 source phase concentration. This new ionophore, therefore, inspiring further to modify and develop a better multinucleating extractant with high lithium loading capacity which is rare in the literature.

Sensing vs Extraction: Functionalized Ionic Liquid as a Single Platform for Dual Applications with Biological Implications

“…To understand the metal–TSIL binding interactions, the nonlinear regression approach was made to derive more reliable binding parameters. Considering the bidentate nature of TSILs, two probable binding models (2:1 and 1:1) were fitted using fluorescence titration data by the BindFit v0.5 program from supramolecular.org, an open-access program. − Out of the two binding models, the 2:1 model is prominent for most of the metal ions except Pd 2+ , which shows a 1:1 fit as evident from the covfit (covariance of the fit, is a measure of the quality of fit) and residual plots . The probable host–guest binding models (Figure S21) with the binding constants, and their links are summarized in Tables S2 and S3.…”

4‐Phosphoryl Pyrazolones for Highly Selective Lithium Separation from Alkali Metal Ions

“…[ 5d , 12 ] Due to its high hydration energy, Li + tends to be less readily extracted than other alkali metal ions. [ 6b , 13 ] Furthermore, very basic conditions (pH>11) are generally required for extraction from aqueous solution. [ 5b , 12c ] Macrocyclic receptors, particular crown‐4 derivatives are also selective for lithium ions and have been widely investigated by SLE (Scheme 1 ).…”

Technology for the Recovery of Lithium from Geothermal Brines

“…All of these approaches have shown some degree of success for selective extraction of lithium from simple solutions. Other ethers have also been shown to have selective chemistry with lithium [197,198].…”