The research team led by Professor Zhang Zhan from SCMU School of Chemistry and Materials Science, in collaboration with Professor Sessler, a foreign academician of the Chinese Academy of Sciences, fellow of the American Academy of Arts and Sciences, and fellow of the European Academy of Sciences, has made significant progress in the synthesis and properties of novel supramolecular framework materials. On September 8, the related findings were published in the prestigious international academic journal Journal of the American Chemical Society (J. Am. Chem. Soc.) under the title "Picric Acid Removal from Water using an Anion-Coordination-Based Supramolecular Organic Framework" (Article link: https://doi.org/10.1021/jacs.5c12626). Wei Huiqi, a master's student from the College of Chemistry and Materials Science, is the first author of the paper, while Associate Professor Wu Lamei, Professor Sessler, and Professor Zhang Zhan are the corresponding authors. Our university is the primary corresponding unit of the paper.

Schematic Diagram of Efficient Picric Acid Removal from Water by Supramolecular Framework Materials. Picture Source: SCMU School of Chemistry and Materials Science

Supramolecular organic framework (SOF) materials, known for their high crystallinity and reusability, hold significant potential in applications such as gas separation, molecular recognition, and photocatalysis. In these contexts, SOF materials typically rely on their porous nature, and the degradation of the material often leads to functional decline or loss. However, recent research by Professor Zhang Zhan's team and Professor Sessler has revealed that the deformation and disassembly of SOF materials could instead serve as advantageous factors in molecular recognition. They synthesized a chloride-SOF material based on the coordination of chloride ions with flexible oligopyrroles. Due to multiple interactions between individual oligopyrrole molecules and the A–B–C stacking mode of the two-dimensional honeycomb layers, the crystalline chloride-SOF exhibits excellent thermal stability and maintains its structure during desolvation. Upon contact with picric acid molecules, this material disassembles and releases monomers, encapsulating and recognizing the picric acid molecules through anion exchange and adaptive structural transformation. This process forms a perfectly shape-matched supramolecular complex with multiple interactions, enabling highly efficient capture of picric acid molecules in water. Under this mechanism, the chloride-SOF material achieves a capture efficiency of over 99.99% for picric acid in water, significantly surpassing conventional covalent organic frameworks (COF), metal-organic frameworks (MOF), and porous organic polymers. After treatment with this material, the picric acid concentration in contaminated water can be reduced from 100 mg/L to the ng/L (ppt) level.

Professor Zhang Zhan's research group primarily focuses on the synthesis and properties of supramolecular compounds and materials, such as organic molecular cages and macrocycles, for molecular recognition. In recent years, the team has achieved a series of research advancements in areas including pollutant removal (J. Am. Chem. Soc. 2025, ASAP), thiol recognition (J. Am. Chem. Soc. 2024, 146, 3585–3590; Chem. Comm., 2021, 57, 1486–1489), fluoride ion recognition (Chem. Comm., 2023, 59, 708–711), bioactive diacid recognition (J. Am. Chem. Soc. 2020, 142, 1987–1994), and alcohol compound recognition (Chem. Comm., 2021, 57, 2772–2775).