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Four new sterically hindered pyridines, L1-L4-containing amido substituents at the 2-position act as efficient solvent extractants for [CoCl4]2− or [ZnCl4]2− from acidic chloride solutions through protonation of the pyridino N-centre to form the neutral outer-sphere complexes [(LH)2MCl4]. These ionophores show very high selectivity for chlorometallate anions over chloride ion and are readily stripped to liberate the free-metal chlorides without the formation of inner-sphere complexes [ML2Cl2]. Single-crystal X-ray structure determinations of [(L2H)2CoCl4] and [(L2H)2ZnCl4] (L2=2-(4,6-di- tert-butylpyridin-2-yl)- N, N′-dihexylmalonamide) coupled with 1H NMR spectroscopy and DFT calculations on L2H+ and other complexes of [ZnCl4]2− confirm that the pyridinium NH group does not address the outer co-ordination sphere of the metallanion, but rather forms a hydrogen bond to the pendant amide groups and thus pre-organizes the ligand to present both CH and amido NH hydrogen-bond donors to the [MCl4]2− ions. The selectivity for chlorometallates over chloride ions shown by this class of extractants arises from their ability to present several polarized CH units towards the charge-diffuse ions [MCl4]2−, whereas the smaller, 'harder' chloride anion prefers to be associated with the amido NH hydrogen-bond donors. [ABSTRACT FROM AUTHOR]