Porous organic polymers decorated with amidoxime hooks for cooperative binding of uranyl. (a) Chemical structures of diamidoxime-functionalized POPs. The numbers in electronvolts were complexation energies calculated from DFT of the shaded units. (b) Single crystal structures of 3 with UO₂. Hydrogen is omitted for clarity. (c) Illustration of POPs with diamidoxime for uranyl extraction. (d) The distribution coefficient values for uranium and vanadium over different sorbent materials (cyan, uranium; red, vanadium). Figure is recreated from Ref [185] by courtesy of the American Chemical Society.