Solid-liquid extraction of lithium chloride with a simple and flexible heteroditopic receptor

The global demand for lithium has surged in recent years due to its wide applications in industry and medicine. We have achieved selective solid-liquid extraction of LiCl using a heteroditopic receptor with an ether linker as a cation recognition site and 2 urea functionalities as cooperative anion recognition sites. The receptor exhibits high selectivity for LiCl from 1H nuclear magnetic resonance (NMR) spectra by complexation in CD3CN and CDCl3. The solid-liquid extraction, followed by stripping to neutral aqueous phase using with the receptor, revealed recovery of LiCl about 90% by ion chromatography and inductively coupled plasma mass spectrometry (ICP-MS) analyses, with a slight competition with MgCl2. LiCl was also recovered from the artificially prepared salt mixture and natural one from the Salar de Uyuni by the solid-liquid extraction with less competitive recovery of MgCl2.