Controlling the Stacking Modes of Metal–Organic Framework Nanosheets through Host–Guest Noncovalent Interactions

• Published in: Angewandte Chemie 2021-03, Vol.133 (13), p.6996-7001
• Main Authors: Tang, Wen‐Qi, Zhao, Ying‐Jie, Xu, Ming, Xu, Jin‐Ya, Meng, Sha‐Sha, Yin, Yun‐Dong, Zhang, Qing‐Hua, Gu, Lin, Liu, Da‐Huan, Gu, Zhi‐Yuan
• Format: Article
• Language: English
• Subjects: Acetic acid; Alkanes; Benzene; Chemical bonds; Chemistry; Ethyl acetate; Gas chromatography; host–guest noncovalent interactions; Hydrocarbons; Hydrophobicity; Isomers; Metal-organic frameworks; nanosheet; Nanosheets; Porosity; separation; Stacking; Steric hindrance; Zirconium
• ISSN: 0044-8249; 1521-3757
• DOI: 10.1002/ange.202014673

The tuning of metal–organic framework (MOF) nanosheet stacking modes from molecular level was rarely explored although it significantly affected the properties and applications of nanosheets. Here, the different stacking modes of Zr‐1, 3, 5‐(4‐carboxylphenyl)‐benzene framework nanosheets were synthesized through the induction of different host–guest noncovalent interactions. The solvents of methyl benzene and ethyl acetate induced twisted stacking of nanosheets with the specific rotation angles of 12°, 18°, 24° and 6°, 18°, 24°, 30°, respectively, which was in agreement with theoretical calculations. Meanwhile, the alkanes were likely to vertically enter the pores of Zr‐BTB nanosheets because of steric hindrance and hydrophobic interactions, resulting in the untwisted stacking of nanosheets. The untwisted ordered nanopores showed the excellent gas chromatographic separations of benzene derivative isomers, which was better than twisted nanosheets stacking and commercial columns. This work uncovers a rational strategy to control the stacking of two‐dimensional MOF nanosheets. The host–guest noncovalent strategy was proposed to tune the stacking modes of metal–organic framework nanosheets for isomer separation. Solvents of methyl benzene and ethyl acetate induced twisted stacking of nanosheets, while the alkanes from C6 to C14 were likely to vertically enter the pores of nanosheets, resulting in the untwisted stacking of nanosheets as efficient isomer separator.