Multivariate Hydrogen‐Bonded Organic Frameworks with Tunable Permanent Porosities for Capture of a Mustard Gas Simulant

Abstract

AbstractPrecise synthesis of topologically predictable and discrete molecular crystals with permanent porosities remains a long‐term challenge. Here, we report the first successful synthesis of a series of 11 isoreticular multivariate hydrogen‐bonded organic frameworks (MTV‐HOFs) from pyrene‐based derivatives bearing −H, −CH3, −NH2 and −F groups achieved by a shape‐fitted, π–π stacking self‐assembly strategy. These MTV‐HOFs are single‐crystalline materials composed of tecton, as verified by single‐crystal diffraction, nuclear magnetic resonance (NMR) spectra, Raman spectra, water sorption isotherms and density functional theory (DFT) calculations. These MTV‐HOFs exhibit tunable hydrophobicity with water uptake starting from 50 to 80 % relative humidity, by adjusting the combinations and ratios of functional groups. As a proof of application, the resulting MTV‐HOFs were shown to be capable of capturing a mustard gas simulant, 2‐chloroethyl ethyl sulfide (CEES) from moisture. The location of different functional groups within the pores of the MTV‐HOFs leads to a synergistic effect, which resulted in a superior CEES/H2O selectivity (up to 94 %) compared to that of the HOFs with only pure component and enhanced breakthrough performance (up to 4000 min/g) when compared to benchmark MOF materials. This work is an important advance in the synthesis of MTV‐HOFs, and provides a platform for the development of porous molecular materials for numerous applications.