Imen Abdelhedi-Miladi’s research while affiliated with Tunis El Manar University and other places

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 (CuAAC) 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 ¹ H, ¹³ C, and ¹⁹ F 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. This article is protected by copyright. All rights reserved

1,3,4‐Trisubstituted 1,2,3‐triazolium salts having either aliphatic or benzylic substituents at the N‐1 and N‐3 positions were synthesized in two steps involving: i) copper(I) catalyzed azide‐alkyne 1,3‐dipolar cycloaddition (CuAAC), and ii) N‐alkylation of the 1,2,3‐triazole intermediates. Trans‐N‐alkylation reactions in bulk and in the presence of excess methyl iodide were monitored by ¹H NMR spectroscopy for each 1,2,3‐triazolium molecular model. By assigning the different formed species and their respective evolution with time, it was possible to conclude that trans‐N‐alkylation exchange reactions are significantly faster for benzylic substituents than for aliphatic ones. Furthermore, the exchange reactions are noticeably faster at the N‐3 position than at the N‐1 position most likely due to the steric hindrance induced by the neighboring C‐4 substituent. The kinetics of trans‐N‐alkylation reactions are thus influenced by both the chemical nature of the N‐1 and N‐3 substituents and the regiochemistry of the 1,2,3‐triazolium group. This provides important structural design rules to improve the properties of thermosetting covalent adaptable networks involving trans‐N‐alkylation of 1,2,3‐triazolium salts.

A series of poly(ionic liquid)s (PILs) incorporating 1,2,3-triazolium and imide units are synthesized in three steps by AA + BB polyaddition between α,ω-diazido tetraethylene glycol and three aromatic bis-imide dipropargyl monomers using copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) followed by N-alkylation of the resulting poly(1,2,3-triazole imide)s with iodomethane and subsequent anion exchange with lithium bis(trifluoromethylsulfonyl)imide. Structure/properties correlations of poly(1,2,3-triazole imide)s and corresponding poly(1,2,3-triazolium imide)s are discussed based on NMR spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), size exclusion chromatography (SEC) and solubility measurements. Graphic Abstract Open image in new window

The patterning of solid electrolytes that builds upon traditional fabrication of semiconductors is described. An azide-functionalized poly(1,2,3-triazolium ionic liquid) is used as an ion conducting negative tone photoresist. After UV-irradiation through an optical mask, micron-scaled, patterned, solid polyelectrolyte layers with controlled sizes and shapes are obtained. Furthermore, alkylation of poly(1,2,3-triazole)s can be generalized to the synthesis of poly(ionic liquid)s with a tunable amount of pendant functionalities.

A series of four 1,2,3-triazolium-based poly(ionic liquid)s (TPILs) is synthesized from the polyaddition of different tailor-made a-azide-?-alkyne monomers by copper(I)-catalyzed azide–alkyne cycloaddition (CuAAC), followed by quaternization with methyl iodide and subsequent anion exchange with lithium bis(trifluoromethylsulfonyl)imide. Whereas the chemical structures of the bis(trifluoromethylsulfonyl)imide counter anion and the N-3 methyl group are common to all TPILs, the structural features of the repeating units, i.e., triethylene glycol or undecanoyl spacers with either ester or ether linkages, are varied and compared. Their impact on the physical and ion-conducting properties of the obtained TPILs is established based on 1H NMR, DSC, thermogravimetric analysis (TGA), and broadband di­electric spectroscopy (BDS) characterization techniques. Most importantly, the replacement of an ether by an ester group at the C-4 position of the 1,2,3-triazolium ring significantly decreases the thermal stability and ionic conductivity of TPILs, whereas the chemical nature of the triethylene glycol or undec­anoyl spacers has little influence on the materials properties.