Synthesis, characterization and chemosensory application of polyfluorenes and poly(fluorene‐ <i>alt</i> ‐benzothiadiazole)s containing tetraphenylethene side chains

Abstract Polyfluorenes and their derivatives containing tetraphenylethenes and nitro‐substituted tetraphenylethenes have been successfully synthesized by the Suzuki–Miyaura cross‐coupling reaction. The presence of nitrated side chains plays an important role in controlling photophysical and electrochemical properties. In addition, the introduction of benzothiadiazole units into the polymer backbone not only lowers bandgap energy but also reduces LUMO energy relative to vacuum. The impacts of solvation on quantum yields and particle sizes were explored by adjusting water fractions. Polyfluorenes with nitro‐substituted tetraphenylethenes show aggregation‐induced emission characteristics. Despite a low quantum yield of the polymers with nitro‐substituted tetraphenylethenes, a deeper LUMO level observed in these polymers is useful for the detection of picric acid. The polymers with tetraphenylethene substituents are more sensitive for the detection of aniline due to an appropriate HOMO level. © 2025 Society of Chemical Industry.