Robustness, Selective Gas Separation, and Nitrobenzene Sensing on Two Isomers of Cadmium Metal–Organic Frameworks Containing Various Metal–O–Metal Chains

• Published in: Inorganic chemistry 2018-10, Vol.57 (20), p.12961-12968
• Main Authors: Liu, Lizhen, Yao, Zizhu, Ye, Yingxiang, Chen, Liangji, Lin, Quanjie, Yang, Yisi, Zhang, Zhangjing, Xiang, Shengchang
• Format: Article
• Language: English
• ISSN: 0020-1669; 1520-510X
• DOI: 10.1021/acs.inorgchem.8b02212

Poor stability has been one of the major difficulties affecting to the practical application of metal–organic frameworks (MOFs). In this work, we obtained two 3D structurally isomeric Cd-MOFs, {[Cd6(NH2Me2)2(PTB)4(HCOO)2(H2O)]·(DMF)13·(H2O)4} n (FJU-35) and {[Cd6(NH2Me2)2(PTB)4(HCOO)2]·(DMF)6·(H2O)2} n (FJU-36) (H3PTB = pyridine-2,4,6-tribenzoic acid) containing different CdII–O–CdII chains by varying the addition agents. FJU-35 with coordinated solvent and formate in asymmetric μ3-η1:η2 coordination mode within the CdII–O–CdII chains is vulnerable to external attacks and is apt to collapse after activation, while FJU-36 with no coordinated solvent in the CdII–O–CdII chains but fully protected by the carboxylates from the ligands and the symmetric formate in the coordination mode μ3-η2:η2 is stable, and its activated sample shows efficient separation of C2H2/CH4 and C2H2/CO2 mixtures. Conversely, FJU-35 with more vulnerability is more sensitive to the detection of nitrobenzene than FJU-36.