Multi Stimuli-Responsive Aggregation-Induced Emission Active Polymer Platform Based on Tetraphenylethylene-Appended Maleic Anhydride Terpolymers

Abstract

Multi stimuli-responsive aggregation-induced emission (AIE) active polymers have great application prospects in high-tech innovations. Herein, three types of tetraphenylethylene (TPE)-containing monomers were synthesized and utilized in preparing TPE-appended maleic anhydride terpolymers. After hydrolysis, the produced TPE-appended maleic acid terpolymers have identical linear charge densities but different “primary” structures, which created widely varied microenvironments around the carboxylate and TPE groups. Benefiting from the synergistic interaction of the TPE moiety and the terpolymer conformation change, the TPE-appended maleic acid terpolymers exhibited fluorescence changes in response to multi stimuli, including pH, ionic strength, Ca2+, and bovine serum albumin. On both the “signaling” and the “stimuli acceptor” sides, the multi stimuli-responsive fluorescence behavior was influenced markedly by the terpolymer primary structure. The fundamental insights gained in the present work are important for developing an efficient and versatile stimuli-responsive AIE-active polymer platform for chemo-sensing, bioimaging, and so on.

Molecular engineering to enhance the reactive oxygen species generation of AIEgens and exploration of their versatile applications

“…(2) Tetraphenyl ethylene (TPE) was considered to be a star molecule due to its unique propeller configuration and was of course a typical AIE material, so TPE was used as the framework and electron donor. 34,35 (3) The difference between organic salt molecules and traditional organic compounds was that their salt structure endowed them with water solubility and ionic properties, which were conducive to cellular uptake. Of course, organic salts were considered to have strong receptor structures.…”

Highly differentiated multi-stimuli-responsive fluorescence performance of tetraphenylethylene-containing styrene–maleic acid copolymers induced by macromolecular architecture control

“…VB-TTC can play the dual roles of the RAFT agent and monomer, thus producing VB-PTSM with a hyperbranched chain topology and TPE as the side groups of branches. PTSM, reported in our previous work 18 and has a linear topology with TPE appended as a side group, was also included for comparison.…”

“…4-Cyano-4-(dodecylsulfanylthiocarbonyl)sulfanylpentanoic acid (CDPA) and 4-(1,2,2-triphenylvinyl)phenol (TPE-OH) were synthesized following procedures reported in our previous work. 18…”

Synthesis and Characterization of Tetraphenylethene AIEgen-Based Push-Pull Chromophores for Photothermal Applications: Do the Cycloaddition – Retroelectrocyclization Click Reaction Could Make any Molecule Photothermally Active?

“…Finally, [2+2] CA-RE reactions were conducted by using a 50% excess of tetracyano derivatives (TCNE, TCNQ and F4-TCNQ) in various solvents at room temperature to afford TPE-TCNE, TPE-TCNQ and TPE-F4-TCNQ respectively, as dark film-forming solids after purification by column chromatography on silica gel (Scheme 3). All the compounds were fully characterized by 1 H, 13 C{ 1 H}, 19 F{ 1 H} NMR spectroscopy and high-resolution mass spectrometry (HR-MS) (see ESI for spectral details). Examining their 1 H NMR spectra, some interesting points can be noted (Figure 1): i) as expected, the grafting of electron withdrawing groups on the triple bond led to a deshielding of the protons located in their vicinity (doublets in the aromatic region) as well as those of the methylene groups bonded to the nitrogen atoms of the aniline moieties (δ = 3.25 -3.55 ppm); ii) the comparison of the chemical shifts of the aromatic protons between TPE-alkyne, TPE-TCNE and TPE-TCNQ highlighted the localization of dicyanoquinomethanyl moiety on the aniline side in agreement with previous findings [54]; iii) due to the highly twisted conformation of the butadiene in TPE-TCNQ (see ESI), all the protons present in the quinoid ring are not equivalents giving rise to four doublets among which two are clearly seen in the figure (see ESI for more details) and iv) the spectrum obtained for TPE-F4-TCNQ, is poorly resolved witnessing the presence of paramagnetic species as observed elsewhere.…”

“…2 of 18 state of molecules, a problem of the utmost importance for many scientific fields or technological applications. [4,7,8] Among the many areas taking advantage of AIEgens, we can mention optoelectronics with OLEDs, [9,10] stimuli-responsive materials, [11][12][13] anticounterfeiting or encryption, [12,14] sensing, [15][16][17] and biology or medicine, fields in which the use of AIEgens has enabled spectacular advances. [18][19][20][21][22][23] Indeed, AIEs are used in the fields of imaging, [24,25] elucidation of biological processes, [26][27][28] innovative therapies such as photodynamic therapy (PDT), [29][30][31] photothermal therapy (PTT), [32,33] sonodynamic therapy enhancement, [34] cocktail therapy [35] and theranostics.…”