Guest-Induced Phase Switching in a Square Lattice Coordination Network to Enable Selective Adsorption of p-Xylene

Guest-Induced Phase Switching in a Square Lattice Coordination Network to Enable Selective Adsorption of p-Xylene

ACS Applied Materials & Interfaces

10.1021/acsami.5c07908

https://doi.org/10.1021/acsami.5c07908

Shi-Qiang Wang, Catiúcia R. M. O. Matos, Shaza Darwish, Volodymyr Bon, Yifei Luo, Jun Zhu, Xiaofei Zhang, Zhengtao Xu, Stefan Kaskel, Michael J. Zaworotko

27 June 2025

Wang, S.-Q., Matos, C. R. M. O., Darwish, S., Bon, V., Luo, Y., Zhu, J., Zhang, X., Xu, Z., Kaskel, S., & Zaworotko, M. J. (2025). Guest-Induced Phase Switching in a Square Lattice Coordination Network to Enable Selective Adsorption of p-Xylene. ACS Applied Materials & Interfaces, 17(27), 39183–39190. https://doi.org/10.1021/acsami.5c07908

Flexible coordination networks (CNs) offer the potential for exceptional selectivity to enable hydrocarbon separations. The key to performance in such sorbents is guest-induced structural transformations that result in induced-fit binding. Unfortunately, the underlying mechanisms of such transformations remain largely unexplored. Herein, we report an investigation of the phase switching behavior of the square lattice (sql) CN [Cu(4,4′-bipyridine)2(CF3CO2)2]n (sql-1-Cu-CF3CO2) induced by xylene adsorption. Competitive adsorption studies in binary and ternary xylene mixtures revealed high p-xylene (PX) selectivity of 10.83 over o-xylene (OX) and of 14.18 over m-xylene (MX), with an overall PX selectivity of 10.01, surpassing most commercial sorbents such as zeolites. Crystallographic studies revealed three distinct xylene-loaded phases with varying pore/channel dimensions and porosity: 1D (void: 33.9%) for PX, 2D (void: 45.8%) for OX, and 3D (void: 48.4%) for MX. The PX-loaded structure exhibited the smallest void but the strongest host–guest interactions, making it the preferred phase for PX separation from xylene mixtures.

Publisher Copyright

This research / project is supported by the Irish Research Council - NA
Grant Reference no. : IRCLA/2019/167

This research / project is supported by the Science Foundation Ireland - NA
Grant Reference no. : 13/RP/B2549 and 16/IA/4624

This research / project is supported by the Agency for Science, Technology and Research - Start-up fund
Grant Reference no. : SC25/22-119116

This research / project is supported by the Agency for Science, Technology and Research - Manufacturing, Trade, and Connectivity Programmatic Fund
Grant Reference no. : M23L8b0049

This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Applied Materials & Interfaces, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see 10.1021/acsami.5c07908

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Institute of Materials Research and Engineering