Effect of Functional Groups on the I2 Sorption Kinetics of Isostructural Metal–Organic Frameworks

• Published in: Bulletin of the Korean Chemical Society Vol. 42; no. 2; pp. 290 - 293
• Main Authors: Lee, Byeongchan, Park, Jinhee
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley‐VCH Verlag GmbH & Co. KGaA 01.02.2021; 대한화학회
• Subjects: Functional group effects; Iodine capture; Metal–organic frameworks; Sorption kinetics; 화학
• ISSN: 1229-5949; 0253-2964; 1229-5949
• DOI: 10.1002/bkcs.12201

In this work, the effect of functional groups on I2 sorption kinetics is investigated using two different types of isostructural metal‐organic frameworks, UiO‐66‐X series (X = H, Br, NO2, NH2, (OH)2, and (COOH)2) and M2(m‐DOBDC) series, (M = Co2+, Mg2+, and Ni2+; m‐DOBDC4− = 4,6‐dioxo‐1,3‐benzenedicarboxylate). Among the UiO‐66‐X series, UiO‐66‐(COOH)2 exhibits the fastest sorption kinetics and the highest sorption capacity due to dipole‐induced dipole interactions between carboxylic acid groups and I2 molecules. In addition, faster I2 chemisorption is observed in M2(m‐DOBDC) because of electrophilic aromatic substitution of m‐DOBDC4− with I2. The I2 sorption mechanisms are further supported by fitting the I2 adsorption kinetics data to pseudo‐first‐order and pseudo‐second‐order kinetic models. The effect of functional groups on I2 sorption kinetics is disclosed using two different metal–organic frameworks, UiO‐66‐X series and M2(m‐DOBDC) series. The dipole‐induced dipole interaction between carboxylic acid groups and I2 molecules significantly enhances the sorption capacity and sorption kinetics of UiO‐66‐(COOH)2. In addition, M2(m‐DOBDC) series exhibits superior I2 sorption kinetics due to electrophilic aromatic substitution of an aryl CH group with I2.