Sequential Pore Wall Modification in a Covalent Organic Framework for Application in Lactic Acid Adsorption

High Resolution Image Download MS PowerPoint Slide Here we describe the synthesis and postsynthetic modification of the stable β-ketoenamine TpBD(NH 2 ) 2 covalent organic framework (COF), having primary amine groups integrated into the pore walls. For this purpose we initially synthesized the nitro version of this COF, TpBD(NO 2 ) 2 . Afterward, TpBD(NO 2 ) 2 was reduced to afford the desired framework having primary amine functionality. We demonstrate the accessibility of the primary amine groups and the robustness of the framework by a second modification step, the aminolysis of acetic anhydride, to obtain the corresponding amide form TpBD(NHCOCH 3 ) 2 . Taking advantage of the high stability of these frameworks under acidic conditions, we study the liquid-phase adsorption of lactic acid, revealing the strong impact of a pore wall modification on the adsorption performance.