Synthesis of Hybridized Nontraditional Intrinsic Luminescent Polymers with Ring-Openable Fused Heterocycles by Facile Multicomponent Polymerizations

The development of nontraditional intrinsic luminescent polymers with unique structures and efficient solid-state luminescence in the absence of remarkable through-bond conjugation is of both fundamental significance and application value. Herein, we report a multicomponent polymerization strategy that can facilely and efficiently synthesize hybridized nontraditional intrinsic luminescent (HNTIL) polymers with entirely new structures, desirable aggregate-state fluorescence, and multiple functionalities. The copper-catalyzed polymerizations of readily available diynes, disulfonyl azides, and chalcone proceed smoothly at room temperature, producing a series of high-molecular-weight (Mw up to 69,500) and heteroatom-rich fused heterocyclic polymers with nonconjugated 2-imino-3,4-dihydrocoumarin units in a highly diastereoselective and atom economic manner. Benefiting from the heteroatom-rich characteristics, all of the obtained polymers possess high refractive index and low chromatic dispersion. By rationally designing the polymer structures, bright and excitation-dependent fluorescence can be achieved in the solid states due to their nontraditional intrinsic luminescent behaviors or aggregation-induced emission properties. The luminescent thin films of the photosensitive HNTIL polymers can be used for the facile fabrication of high-contrast fluorescent photopatterns. Furthermore, a new heterochain HNTIL polymer with brighter aggregate-state fluorescence can be formed by the reduction ring-opening reaction of the nonconjugated fused heterocyclic polymer, allowing for the diversification of the polymer structure and the modulation of photophysical properties.