Clickable Polymerization-Induced Emission Luminogens Toward Color-Tunable Modification of Non-Traditional Intrinsic Luminescent Polymers

Non-traditional intrinsic luminescent (NTIL) polymer is an emerging field, and its color-tunable modification is highly desirable but still rarely investigated. Here, a click chemistry approach for the color-tunable modifications of NTIL polymers by introducing clickable polymerization-induced emission luminogen (PIEgen), is demonstrated. Through Cu-catalyzed azide-alkyne cycloaddition click chemistry, a series of PIEgens is successful prepared, which is further polymerized via reversible addition-fragmentation chain transfer (RAFT) polymerization. Interestingly, after clickable modification, these monomers are nonemissive in both solution and aggregation states; while, the corresponding polymers exhibit intriguing aggregation-induced emission (AIE) characteristics, confirming their PIEgen characteristics. By varying alkynyl substitutions, color-tunable NTIL polymers are achieved with emission wavelength varying from 448 to 498 nm, revealing a series of PIEgens and verifying the importance of modification of NTIL polymers. Further luminescence energy transfer application is carried out as well. This work therefore designs a series of clickable PIEgens and opens a new avenue for the modification of NTIL polymers via click chemistry, which may cause inspirations to the research fields including luminescent polymer, NTIL, click chemistry, AIE and modification.

Barbier Polymerization-Induced Emission towards Fully Substituted Polyethylene Analogues with Non-Traditional Intrinsic Luminescence

The properties of polyethylene are highly dependent on the variety and quantity of substitutions. Generally, polyethylene can only be fully substituted with fluorine atoms, mainly e. g., polytetrafluoroethylene and nafion, because atomic radius of fluorine atom is small enough. The preparation of fully substituted polyethylene analogues (FSPEA) and their non-traditional intrinsic luminescence (NTIL) are attractive, especially for substitutions with relatively larger atomic radii than a fluorine atom. Here, Barbier polymerization-induced emission (PIE) is demonstrated as a universal method for the molecular design of NTIL type FSPEAs with intriguing aggregation-induced emission (AIE) behaviors. Through Barbier polymerization of diphenyldichloromethane and different peroxyesters in the presence of Mg in one pot, a series of FSPEAs, including polytriphenylethanol (PTPE), polydiphenylfurylethanol (PDPFE), polydiphenylthiophenylethanol (PDPTE) and polydiphenylnaphthylethanol (PDPNE) have been successfully prepared. Further potential applications for explosive detection, artificial light-harvesting system and white phosphor-converted light-emitting diode are investigated. Therefore, this work opens up a new approach for the molecular design of FSPEA with non-conjugated luminescence, which may cause inspirations to different research fields like polyolefin and luminescent materials.

Recent progress on polymerization-induced emission

The aggregate luminescence behaviors of polymeric luminescent materials have been attracting great attention. However, the importance of the polymerization process on luminescence, namely, polymerization-induced emission (PIE), has rarely been overviewed. In this review, recent advances in polymerization with PIE effects are summarized, including PIE with aromatic rings based on one-/two-/multi-component polymerizations, and PIE without aromatic rings according to disparate mechanisms of polymerizations. Typical examples are selected to elaborate the basic design principles, as well as the properties and potential applications of the luminous polymers. Moreover, the challenges and perspectives in this area are also discussed.

Ketyl Radical Anion Mediated Radical Polymerization and Anionic Ring-Opening Polymerization to Give Polymers with Low Molecular Weight Distribution

The development of novel polymerization capable of yielding polymers with low molecular weight distribution (Đ) is essential and significant in polymer chemistry, where monofunctional initiator contains only one initiation site in these polymerizations generally. Here, ketyl radical anion species is introduced to develop a novel Ketyl Mediated Polymerization (KMP), which enables radical polymerization at carbon radical site and anionic ring-opening polymerization at oxygen anion site, respectively. Meanwhile, polymerization and corresponding organic synthesis generally couldn't be performed simultaneously in one pot. Through KMP, organic synthesis and polymerization are achieved in one pot, where small molecules (cyclopentane derivates) and polymers with low Đ are successfully prepared under mild condition simultaneously. At the initiation step, both organic synthesis and polymerization are initiated by single electron transfer reaction with ketyl radical anion formation. Cyclopentane derivates are synthesized through 3-3 coupling reaction and cyclization. Polystyrene and polycaprolactone with low Đ and a full monomer conversion are prepared by KMP via radical polymerization and anionic ring-opening polymerization, respectively. This work therefore enables both organic synthesis and two different polymerizations from same initiation system, which saves time, labour, resource and energy and expands the reaction mode and method libraries of organic chemistry and polymer chemistry.

Recent Advances and Challenges in Barbier Polymerization

The Barbier reaction, a classical name reaction for carbon-carbon bond formation, has played important roles in organic chemistry for over 120 years. The introduction of the Barbier reaction into polymer chemistry for the development of a novel Barbier polymerization, expands the methodology, monomer, chemical structure and property libraries of polymerization, aggregation-induced emission (AIE) and non-traditional intrinsic luminescence (NTIL). This mini review focuses on Barbier polymerization, including the brief introduction of the history and importance of polymerization methods design and the achievements of Barbier polymerization from molecular design strategies, functionalities and properties. An outlook of Barbier polymerization is also proposed. This mini review on Barbier polymerization therefore may cause inspirations to scientists in different fields.

Barbier polymerization induced emission of cinnamaldehyde: a one-pot Grignard reaction?

The Grignard reaction of cinnamaldehyde is demonstrated to give a 1,2-addition product, while the Barbier reaction of cinnamaldehyde yields a macromolecule with aggregation-induced emission type non-conjugated luminescence properties.