Nucleophilic Substitution Polymerization-Induced Emission of 1,3-Dicarbonyl Compounds as a Versatile Approach for Aggregation-Induced Emission Type Non-Traditional Intrinsic Luminescence†

Nucleophilic substitution reaction and 1,3-dicarbonyl compounds play significant roles in organic chemistry, and non-traditional intrinsic luminescence (NTIL) has become an emerging research area. Here, we demonstrate the successful nucleophilic substitution polymerization of 1,3-dicarbonyl compounds, including acetylacetone, 3,5-heptanedione, methyl acetoacetate, cyclopentane-1,3-dione, 1,3-indandione, 1-phenyl-1,3-butanedione and dibenzoylmethane, where reactive hydrogens at a position of 1,3-dicarbonyl compounds are involved. Through this base catalyzed nucleophilic substitution polycondensation between 1,3-dicarbonyl compounds and a,a'-dibromo xylene, a series of nonconjugated poly(1,3-dicarbonyl)s have been successfully prepared with high yield (up to >99%) under mild conditions. Investigations reveal that this nucleophilic substitution polycondensation exhibits self-accelerating effect and flexible stoichiometry characteristics, which exhibits advantages over traditional polycondensation methods. This polymerization also exhibits intriguing polymerization-induced emission (PIE) characteristics, where nonconjugated poly(1,3-dicarbonyl)s exhibit intriguing chemical structure dependent aggregation-induced emission (AIE) type NTIL. This work therefore expands the monomer, method, chemical structure and property libraries of polymer chemistry, which may cause inspirations to polymerization methodology, PIE, AIE and NTIL.

Automated summary

This study successfully demonstrated the nucleophilic substitution polymerization of 1,3-dicarbonyl compounds and showed the advantages of this method, such as faster reaction rates and milder reaction conditions. Additionally, it was found that this polymerization exhibits polymerization-induced emission characteristics, and nonconjugated polymers showed aggregation-induced emission dependent on their chemical structure. This work expands the libraries of monomers, methods, chemical structures, and properties in polymer chemistry, and may inspire advancements in polymerization methodology, polymerization-induced emission, aggregation-induced emission, and non-traditional intrinsic luminescence.