Synthesis of a Water-Soluble, Soft N-Donor BTzBP Ligand Containing Only CHON

Abstract

A hydrophilic ligand that contains only C, H, O, and N substituents and uses a 6,6′-bis(1H-1,2,3-triazol-4-yl)-2,2′-bipyridine (BTzBP) structural core has been synthesized. The effect of adding water-soluble groups onto extractant ligands has been extensively studied to facilitate the efficient partitioning of 4f and transuranic 5f elements for the treatment of spent nuclear fuel. Soft, N-donor ligands exhibit greater binding affinities for the trivalent actinides over the trivalent lanthanides, making BTzBP ligands an ideal candidate in the search for extractants to be used on an industrial scale. To date, hydrophobic BTzBPs have been shown to exhibit physical and chemical properties that might be conducive to nuclear waste processing conditions. However, hydrophilic BTzBPs have yet to be reported. Herein, we show the synthesis of a hydrophilic BTzBP ligand featuring cationic water solubilizing groups attached to the bipyridal rings.