Ethynyl-Capped Hyperbranched Conjugated Polytriazole: Click Polymerization, Clickable Modification, and Aggregation-Enhanced Emission

Abstract

Cu(I)-catalyzed azide−alkyne click polymerization, developed based on the click reaction, has become a powerful tool for the construction of functional polytriazoles with linear and hyperbranched structures. This method has, however, rarely been used for the preparation of functional hyperbranched conjugated polytriazoles (hb-CPTA). In this paper, soluble ethynyl-capped hb-CPTA with weight-averaged molecular weight of 39 500 was synthesized in high yield (84.4%) by the Cu(I)-catalyzed azide−alkyne click polymerization of tetraphenylethene containing diazide [1,2-bis(4-azidophenyl)-1,2-diphenylethene] and tetrayne [1,1,2,2-tetrakis(4-ethynylphenyl)ethane] in equal concentration. By taking advantage of the ethynyl groups on its periphery, the polymer could be efficiently postfunctionalized by azide−alkyne and thiol−yne click reactions. The polymers are thermally stable and loss 5% of their weights at temperatures higher than 340.0°C. hb-CPTA also possesses high char yield (74.8%) at 800°C. The polymers feature the unique characteristics of aggregation-enhanced emission. Furthermore, the PL intensities of the hb-CPTA and thiol−yne postfunctionalized polytriazoles increase linearly with water fraction in THF/water mixtures. Thanks to their rigid structures, the polymers could be fabricated into unimolecular nanoparticles with sizes of ca. 100 nm. Thus, this paper provides a powerful method to synthesize soluble ethynyl-capped hyperbranched polymers, which could be a useful platform for preparation of versatile functional polymers via postreactions.

Synthesis, characterization and investigation of proton exchange properties of sulfonated polytriazoles from a new semifluorinated diazide monomer

“…. Subsequently, this reaction has been exploited to a large extent in polymer chemistry for synthesizing linear polymers , hyperbranched copolymers , graft copolymers , block copolymers , and polymer‐composites .…”

A neutral branched platinum–acetylide complex possessing a tetraphenylethylene core: preparation of a luminescent organometallic gelator and its unexpected spectroscopic behaviour during sol-to-gel transition

“…The intermediate tetrakisalkynyl-substituted tetraphenylethylene 1 was readily synthesized in three steps from 4,4'-dibromobenzophenone according to the reported procedures. 12 The platinum-acetylide complex 2 was then prepared via the cross-coupling reaction of 1 with trans-PtI 2 (PMe 3 ) 2 catalyzed by CuI in a mixture solvent of THF and diethylamine at room temperature. Finally, the similar coupling reaction of the intermediate 2 with the terminal acetylene compound 3 bearing long alkyl chain resulted in the target complex TPA in high yield.…”

“…S4, when the concentration of TPA was increased from 5.0 × 10 -4 to 8.0 × 10 -3 M, the resonance signals corresponding to the amide proton displayed a gradual downfield from δ = 7.62 to 7.67 ppm, which was indicative of the existence of hydrogen-bonding interactions during the formation of supramolecular aggregate in TPA. Moreover, it has been reported that fluoride anion (F -) can induce a deprotonation process of amide group, 12 thereby disturbing the hydrogen-bonding between amides. Therefore, the existence of hydrogen bonding interactions during the self-assembly process could be further supported by studying the stability of organometallic gel after the addition of F into the gel of TPA.…”

Tetraphenylethene‐Based Conjugated Fluoranthene: A Potential Fluorescent Probe for Detection of Nitroaromatic Compounds

“…A solution of 1 (0.070 g, 0.16 mmol) and 3 (0.34 g, 0.98 mmol) in diphenyl ether (8 mL) were added to a hydrothermal bomb and heated for 24 h in a 200 °C oven. Then the reaction mixture was cooled to room temperature, loaded into a column of silica gel, and the product was separated by using dichloromethane/hexane (1:9) as the eluent to obtain the desired product as a pale‐yellow solid (130 mg, 46 %).…”