Optimizing Fe‐Based Metal‐Organic Frameworks through Ligand Conformation Regulation for Efficient Dye Adsorption and C2H2/CO2 Separation. Issue 41 (27th May 2021)

• Record Type: Journal Article
• Authors: Zhang, Xiurong; Fan, Weidong; Jiang, Weifeng; Li, Yue; Wang, Yutong; Fu, Mingyue; Sun, Daofeng
• Is Part Of: Chemistry. Volume 27:Issue 41(2021)
• Page Start: 10693
• Page End: 10699
• Publication Date: 2021-05-27
• Subjects: dye adsorption -- gases separation -- ligand conformation regulations -- metal-organic frameworks; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.202101053
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: Regulating the structure of metal‐organic frameworks (MOFs) by adjusting the ligands reasonably is expected to enhance the interaction of MOFs on special molecules/ions, which has significant application value for the selective adsorption of guest molecules. Herein, two tricarboxylic ligands H3 L−Cl and H3 L−NH2 were designed and synthesized based on the ligand H3 TTCA by replacing part of the benzene rings with C=C bonds and modifying the chlorine and amino groups on the 4‐position of the benzene ring. Two 3D Fe‐MOFs (UPC‐60‐Cl and UPC‐60‐NH2 ) with the new topology types were constructed. As the C=C bonds of the ligands have flexible torsion angles, UPC‐60‐Cl features three types of irregular 2D channels, while UPC‐60‐NH2 has a cage with two types of windows on the surface. The synergistic effect of unique channels and modification of functional groups endows UPC‐60‐Cl and UPC‐60‐NH2 with high adsorption capacity for organic dyes. Compound UPC‐60‐Cl shows high adsorption capacity for CV (147.2 mg g −1 ), RHB (100.3 mg g −1 ), and MO (220.9 mg g −1 ), whereas UPC‐60‐NH2 exhibits selective adsorption of MO (158.7 mg g −1 ). Meanwhile, based on the diverse pore structure and modification of active sites, UPC‐60‐Cl and UPC‐60‐NH2 show the selective separation of equimolar C2 H2 /CO2 . Therefore, reasonable regulation of organic ligands plays a significant role in guiding the structure diversification and performance improvement of MOFs. Abstract : Two 3D Fe‐MOFs (UPC‐60‐Cl and UPC‐60‐NH2 ) were constructed based on UPC‐200(Fe)‐H‐H2 O by replacing part of the benzene rings with C=C bonds and modifying −Cl− and −NH2 on the ligand. The synergistic effect of diversified structure and modification of functional groups endow UPC‐60‐Cl and UPC‐60‐NH2 with high adsorption capacity for dyes and good C2 H2 /CO2 separation ability. Through reasonable regulation of ligands with functional groups, the structure can be precisely regulated to achieve the adsorption and separation of specific guest molecules.