Molecular Recognition by a Tris(phenylisoxazolyl)Benzene Derivative Under Flow‐Through Conditions

ABSTRACT The application of host molecules as separation media has attracted considerable attention owing to their intrinsic molecular recognition capabilities. Herein, we report the host–guest complexation behavior of a tris(phenylisoxazolyl)benzene derivative under flow‐through conditions. After thermal activation, the tris(phenylisoxazolyl)benzene derivative preferentially retains cis ‐decalin under flow‐through conditions in the presence of octane, mesitylene, and trans ‐decalin to afford >95% removal of cis ‐decalin in the early‐eluting fractions. Even after most of octane, mesitylene, or trans ‐decalin had eluted, cis ‐decalin remained retained in the column over the measured elution range. Calculations using the dimeric cavity of the tris(phenylisoxazolyl)benzene derivative provides a plausible structural rationale for the observed selectivity trends. Practically, this derivative maintains cis ‐decalin removal performance under acidic and basic conditions and after 365 nm irradiation. Moreover, it can be regenerated with no discernible performance loss over at least ten adsorption–regeneration cycles, highlighting its chemical/photochemical tolerance and reusability. This study underscores the potential advantages of the metal‐free architecture of the tris(phenylisoxazolyl)benzene derivative, which maintains separation performance under acidic/basic conditions and UV irradiation. This may lead to the deployment of the tris(phenylisoxazolyl)benzene derivative and related non‐macrocyclic hosts as scalable, selective media for flow‐through separations of hydrocarbon mixtures.