2,6-Lutidine (2,6-LT) is a very important raw material in the chemical industry, but the impurities of 3-picoline (3-PC) and 4-picoline (4-PC) existing in 2,6-LT seriously affect its quality. Considering different molecular sizes of these three compounds, herein, we exploit nonporous adaptive crystals (NACs) of pillararenes as purifying agents for removal of 3-PC and 4-PC in 2,6-LT. We find that per-ethylated pillararene (EtP5) can selectively adsorb 3-PC and 4-PC, while negligible capture of 2,6-LT is observed, resulting in improvement of the purity of 2,6-LT up to 94.9%. Single-crystal structures indicate that the excellent selectivity originates from the size match and complexation stability differences among different host/guest pairs. After purification, NACs of EtP5 can be easily regenerated and used in the next run without a significant performance degradation.
Bibliographical noteKAUST Repository Item: Exported on 2022-09-14
Acknowledged KAUST grant number(s): OSR-2019-CRG8-4032
Acknowledgements: This work was supported by the National Key Research and Development Program of China (2021YFA0910100), the National Natural Science Foundation of China (22035006), the Zhejiang Provincial Natural Science Foundation of China (LD21B020001), the Starry Night Science Fund of Zhejiang University Shanghai Institute for Advanced Study (SN-ZJU-SIAS-006), and the King Abdullah University of Science and Technology Office of Sponsored Research (OSR-2019-CRG8-4032). The authors thank Wendi Chen from Shiyanjia Lab (www.shiyanjia.com) for the SXRD analysis.
This publication acknowledges KAUST support, but has no KAUST affiliated authors.
ASJC Scopus subject areas
- General Materials Science