A Pillar[6]arene-Based Solid-State Supramolecular Polymer Exhibiting a Vapochromic Response for VOC Detection

Solid-state supramolecular polymers based on exo-wall macrocycle-guest complexation are promising for designing functional materials. In this work, we investigate the host–guest complexation of perethylated pillar[6]arene (EtP6) with halogenated guests tetrafluorophthalic anhydride, tetrachlorophthalic anhydride, and tetrabromophthalic anhydride. EtP6 exhibits relatively strong binding affinity toward these guests via charge-transfer interactions. Notably, leveraging the exo-wall complexation between EtP6 and tetrachlorophthalic anhydride, we constructed a linear solid-state supramolecular polymer. By exploiting the unoccupied cavity of EtP6 and the structural rearrangement of the supramolecular polymer, we achieved efficient vapochromic detection and adsorption of a broad range of volatile organic compounds (VOCs). This study not only introduces a solid-state supramolecular polymer but also provides an innovative strategy for designing vapochromic materials for VOC sensing and capture, demonstrating significant potential for environmental monitoring and health protection applications.