2,6-Diiminopiperidin-1-ol: an overlooked motif relevant to uranyl and transition metal binding on poly(amidoxime) adsorbents.

ABSTRACT

Glutardiamidoxime, a structural motif on sorbents used in uranium extraction from seawater, was discovered to cyclize in situ at room temperature to 2,6-diimino-piperidin-1-ol in the presence of uranyl nitrate. The new diimino motif was also generated when exposed to competing transition metals Cu(ii) and Ni(ii). Multinuclear µ-O bridged U(vi), Cu(ii), and Ni(ii) complexes featuring bound diimino ligands were isolated.