Outer-sphere amidopyridyl extractants for zinc(<scp>ii</scp>) and cobalt(<scp>ii</scp>) chlorometallates

Abstract

Protonated amidopyridyl ligands show high selectivity for the extraction of [CoCl(4)](2-) or [ZnCl(4)](2-) over chloride ion into organic media via the formation of N-H and C-H hydrogen-bond donors to the outer coordination spheres of the chlorometallates.