Figure 4.

Modification of COF Structures

(A) Synthetic scheme of COF-TpDb-AO.

(B–D) (B) Graphic view of the eclipsed AA stacking structure of COF-TpDb and COF-TpDb-AO.¹⁸¹ (C) Space-filling view of the structure of (a and b) COF-SO₃H and (c) [NH₄]⁺[COF-SO₃⁻]. The COF-SO₃H shows the ABA stacking fashion, which means that the arrangement of -SO₃H in the layers (a) and (b) is in the opposite mode rather than the common same-side mode (see the insert); the location of NH₄⁺ and the hydrogen bond interactions between NH₄⁺ and COF skeleton are highlighted (see the insert). (D) View of the DFT optimized uranyl-loaded structure for the [NH₄]⁺[COF-SO₃⁻] samples.⁸²