Synthesis of crescent aromatic oligoamides with preorganized chelating groups and their extraction towards transition metal ions

► Three crescent aromatic oligoamides were designed and synthesized. ► Selective Hg2+ removal was achieved with high efficiency in solvent extraction. ► The stoichiometry of the extracted species was approximately 1:1 (L:M). ► The extraction constant (log Kex) was determined to be 10.2.