Fluorinated 1,2,4-Oxadiazole-Based Supramolecular Systems for Wastewater Pollutants Sensing

Abstract

Fluorinated compounds have become key components of advanced functional materials, acting as building blocks or structural elements that extend well beyond their conventional applications.1 For example, low-molecular-weight gels (LMWGs) based on fluorinated systems are emerging as highly relevant supramolecular materials.2 In this study, a new set of fluorinated 1,2,4-oxadiazole derivatives were synthesized to investigate their self-assembly potential. Structural diversity was introduced by varying the substituents at the C3 and C5 positions of the oxadiazole, employing aliphatic and aromatic amines or amino acids, as well as fluorinated and non-fluorinated side chains. These modifications led to marked differences in physicochemical behaviour by tuning key intermolecular interactions, including fluorous phase segregation, π-π stacking, hydrogen bonding, and dispersive forces, resulting in distinct supramolecular organization such as photonic liquids (PLs) and organogels. In addition, cytotoxicity assays indicate that the derivatives in Figure 1 are non-toxic toward RPE-1 cells at a concentration of 10-3 M, supporting their potential use in environmentally relevant sensing applications. Such features make these materials promising candidates for the detection of wastewater pollutants such as per- and polyfluoroalkyl substances (PFAS), exploiting probable selective fluorine-fluorine interactions and affinity-driven partitioning within fluorous domains.3 The tunable supramolecular organization is expected to enable sensitive and selective sensing responses, while also suggesting potential applications in biomedicine, for instance in bioimaging or drug delivery.