Barbier Hyperbranching Polymerization‐Induced Emission from an AB‐Type Monomer

Abstract

Luminescent polymer materials have gained considerable research efforts in the past decades and are generally molecular designed by extending the π system of the polymer main chain or by incorporating chromophores into the polymer chain, which suffer from poor solubility, difficult synthesis, or multi-step procedures. Meanwhile, according to the step-growth polymerization theory, synthesis of hyperbranched polymers from an AB-type monomer is still challenging. Herein, we report a one-pot synthesis of nonconjugated luminescent hyperbranched polymer material via Barbier hyperbranching polymerization-induced emission (PIE) from an AB-type monomer. The key step in the realization of the hyperbranched polymer is bi-functionalization of a mono-functional group. Through a Barbier reaction between an organohalide and an ester group in one pot, bifunctionalization of mono-functional ester is realized through two-step nucleophilic additions, resulting in hyperbranched polytriphenylmethanols (HPTPM). Attributed to throughspace conjugation and inter-and intramolecular chargetransfer effects induced by polymer chain, nonconjugated HPTPMs are PIEgens, which are tunable by monomer structure and polymerization time. When all phenyl groups are rotatable, HPTPM is aggregation-induced emission type PIEgen. Whereas, it is aggregation-caused quenching type PIEgen if some phenyl groups are rotation forbidden. Further potential applications of PIEgen are in the fields of explosive detection and artificial light harvesting systems. This work, therefore, expands the monomer library and molecular design library of hyperbranched polymers through "bi-functionalization of mono-functional group" strategy, which eventually expands the preparation library of nonconjugated luminescent polymer materials through one-pot PIE from nonemissive monomer.

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

“…For example, polyesterification, polyamidation, coupling polymerizations, ring‐ opening metathesis polymerization, click polymerization, Michael polymerization, multicomponent polymerization, living polymerizations and Barbier polymerization, are based on corresponding esterification, amidation, coupling reactions, olefin metathesis reaction, click reaction, Michael reaction, multicomponent reaction, reversible‐deactivation reactions and Barbier reaction, respectively. [ 12,17‐18,25‐46 ] Further exploration of polymerization methods will expand the monomer, polymer and functionality libraries of polymer chemistry, which will eventually result in the prosperous polymer science with abundant synthetic polymers for a better human life.…”

Radical Polymerization-Induced Nontraditional Intrinsic Luminescence of Triphenylmethyl Azide-Containing Polymers

“…Therefore, it is very promising to expand the molecular library of PIEgen and investigate the PIE effect. For examples, through Barbier polymerization of AB, A 2 + B 2 , AB 2 , and A 2 + B type monomers, PIE is proposed, and a series of NTIL polymers have been molecularly designed by PIE strategy with a series of novel PIEgens, including triphenylmethanol and triphenylethanol. ,,,− Through this Barbier polymerization, the luminescent types of these NTIL polymers can be adjusted from aggregation-caused quenching (ACQ) to aggregation-induced emission (AIE). NTIL polymers have also been molecularly designed through different polymerization methods, including but not limited to Michael polyaddition, click polymerization, and multicomponent reaction. ,,− Reversible addition–fragmentation chain transfer (RAFT) polymerization is a versatile polymerization method, which enables polymer chain with narrow molecular weight distribution and has received considerable research attention in the past decades. − Further investigation on the molecular design of novel PIEgens through RAFT PIE is therefore attractive.…”

Compatibility of Barbier Covalent-Anionic-Radical Polymerization with Air and Divinylbenzene

“…The Barbier reaction, developed by Phillippe Barbier in 1899, is a successful C–C bond formation reaction through nucleophilic addition reaction between organohalides and carbonyls in the presence of metals (e.g., Mg). − Compared with the analogous Grignard reaction, developed by Victor Grignard (Phillippe Barbier’s PhD student) in 1900, the Barbier reaction exhibits reactive hydrogen tolerance, attributed to its unique 3-in-1 covalent-anion-radical mechanism, which can be achieved under mild conditions in one pot. Since 2017, the Barbier reaction has been introduced into polymer chemistry successfully, where a series of hydroxyl- and amine-containing polymers have been prepared with intriguing properties through step-growth Barbier polymerization. − Attributed to the unique 3-in-1 covalent-anion-radical characteristics of polymerization species, chain-growth covalent-anionic-radical polymerization (CARP) was developed, where polymers with full monomer conversion and Đ low to 1.05 were prepared under an inert atmosphere. − Meanwhile, divinylbenzene (DVB) typically gives highly cross-linked polymers insoluble in solvents by both radical and anionic polymerization, which are commonly used as ion-exchange resins and chromatography columns . The preparation of soluble DVB-containing polymers is still challenging, especially for the preparation of DVB-containing polymers with close to 100% vinyl side chains at high DVB conversion.…”