Nonconventional Clusteroluminescence From Cationic Polymerization Derived Unconjugated Poly(2,3‐Dihydrofuran)

Recently, nonconventional luminescent polymers have gained significant attention as promising alternatives to traditional fluorescent polymers, addressing and overcoming many of their limitations. In this work, a new class of nonconjugated polymers derived from 2,3‐dihydrofuran (DHF) has been reported, which exhibit bright emission in both solid and solution states, despite the absence of conjugation or conventional chromophores in poly(2,3‐dihydrofuran) (PDHF). PDHF polymers with different molecular weights were synthesized by cationic polymerization of DHF in toluene at −55°C in the presence of tin(IV) chloride (SnCl 4 ) as catalyst and tert ‐butyl chloride ( t BuCl) as initiator. These polymers exhibit excitation‐dependent emission, indicating the presence of multiple emissive states. Notably, a marked enhancement in emission intensity was observed under concentrated conditions and in the presence of nonsolvents (hexane and water), indicative of their aggregation‐induced emission behavior. On the other hand, the optical transparency of PDHF in the visible region in combination with the intrinsic fluorescence, makes it a potential candidate for data encryption and related applications, such as security printing using invisible inks. In summary, this work offers a clear and in‐depth understanding of the photoluminescent behavior of PDHF and its potential future applications.