1,3,4,5-Tetrasubstituted Poly(1,2,3-triazolium) Obtained through Metal-Free AA+BB Polyaddition of a Diazide and an Activated Internal Dialkyne

A tetra(ethylene glycol)-based 1,3,4,5-tetrasubstituted poly(1,2,3-triazolium) is synthesized in two steps including: i) the catalyst-free polyaddition of a diazide and an activated internal dialkyne and ii) the N-alkylation of the resulting 1,2,3-triazole groups. In order to provide detailed structure/properties correlations different analogs are also synthesized. First, parent poly(1,2,3-triazole)s are obtained via AA+BB polyaddition using copper(I)-catalyzed alkyne-azide cycloaddition or metal-free thermal alkyne-azide cycloaddition (TAAC). Poly(1,2,3-triazole)s with higher molar masses are obtained in higher yields by TAAC polyaddition. A 1,3,4-trisubstituted poly(1,2,3-triazolium) structural analog obtained by TAAC polyaddition using a terminal activated dialkyne and subsequent N-alkylation of the 1,2,3-triazole groups enables discussing the influence of the methyl group in the C-4 or C-5 position on thermal and ion conducting properties. Obtained polymers are characterized by 1H, 13C, and 19F NMR spectroscopy, differential scanning calorimetry, thermogravimetric analysis, size exclusion chromatography, and broadband dielectric spectroscopy. The targeted 1,3,4,5-tetrasubstituted poly(1,2,3-triazolium) exhibits a glass transition temperature of -23 °C and a direct current ionic conductivity of 2.0 × 10-6 S cm-1 at 30 °C under anhydrous conditions. The developed strategy offers opportunities to further tune the electron delocalization of the 1,2,3-triazolium cation and the properties of poly(1,2,3-triazolium)s using this additional substituent as structural handle.

Recent Advances on Fabrication of Polymeric Composites Based on Multicomponent Reactions for Bioimaging and Environmental Pollutant Removal

As the core of polymer chemistry, manufacture of functional polymers is one of research hotspots over the past several decades. Various polymers are developed for diverse applications due to their tunable structures and unique properties. However, traditional step-by-step preparation strategies inevitably involve some problems, such as separation, purification, and time-consuming. The multicomponent reactions (MCRs) are emerging as environmentally benign synthetic strategies to construct multifunctional polymers or composites with pendant groups and designed structures because of their features, such as efficient, fast, green, and atom economy. This mini review summarizes the latest advances about fabrication of multifunctional fluorescent polymers or adsorptive polymeric composites through different MCRs, including Kabachnik-Fields reaction, Biginelli reaction, mercaptoacetic acid locking imine reaction, Debus-Radziszewski reaction, and Mannich reaction. The potential applications of these polymeric composites in biomedical and environmental remediation are also highlighted. It is expected that this mini-review will promote the development preparation and applications of functional polymers through MCRs.

Aggregation-Induced Emission Active Polyacrylates via Cu-Mediated Reversible Deactivation Radical Polymerization with Bioimaging Applications

The introduction of aggregation-induced emission (AIE) moieties into polymers results in smart materials with AIE characteristics, expanding their scope of applications. Herein, well-defined polymers with controlled molecular weight, low dispersity, and high end-group fidelity are produced via copper(0)-mediated reversible-deactivation radical polymerizations (Cu(0)-RDRPs). An AIE-containing initiator tetraphenylethene bromoisobutyrate (TPEBIB) has been synthesized, fully characterized, and utilized for the construction of different polyacrylate homopolymers and block copolymers bearing the TPE group with a range of molecular weights and architectures. All of the polymers exhibited AIE behavior. Notably, the hydrophobic TPE-poly(tert-butyl acrylate) (TPE-PtBA)-containing block copolymers are transformed to TPE-poly(acrylic acid) (TPE-PAA)-based amphiphilic copolymers by facile deprotection, enabling pH-tunable self-assembly in aqueous media to give fluorescent nanoparticles with various sizes. The low cytotoxicity, high specificity, and excellent photostability render them promising candidates as lysosome-specific probes in biological imaging applications.

Metal-free polycycloaddition of aldehyde-activated internal diynes and diazides toward post-functionalizable poly(formyl-1,2,3-triazole)s

A metal-free polycycloaddition of aldehyde-activated internal diynes and diazides was successfully established and post-functionalizable poly(formyl-1,2,3-triazole)s were readily produced.

Ferrocene-based hyperbranched poly(phenyltriazolylcarboxylate)s: synthesis by phenylpropiolate-azide polycycloaddition and use as precursors to nanostructured magnetoceramics

Ferrocene-based hb-PPTCs with redox activity are readily prepared by the catalyst-free phenylpropiolate-azide polycycloaddition. They could be used as precursors to produce nanostructured magnetoceramics upon pyrolysis.