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ABSTRACT: The metal-free click polymerizations (MFCPs) of activated alkynes and azides have become a powerful technique for the preparation of functional polytriazoles. Recently, a new MFCP of activated azide and alkyne has been established, but no functional polytriazole is prepared. In this paper, polytriazole PIa with aggregation-enhanced emission (AEE) characteristics is prepared by this efficient polymerization in excellent yield (97.9%). PIa is thermally stable, with 5% loss of its weight at temperature as high as 440 °C. Thanks to its unique AEE feature of PIa, its nanoaggregates can be used to detect explosives with a superamplification quenching effect.
Macromolecular Rapid Communications 03/2013; · 4.60 Impact Factor
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Jian Zhou,
Zhengfeng Chang,
Yibin Jiang,
Bairong He,
Man Du,
Ping Lu,
Yuning Hong,
Hoi Sing Kwok, Anjun Qin,
Huayu Qiu,
Zujin Zhao,
Ben Zhong Tang
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ABSTRACT: Replacement of phenyl ring(s) in tetraphenylethene by naphthalene ring(s) generates a series of new luminogens with aggregation-induced emission (AIE) characteristics, demonstrating that bulky naphthalene rings can serve as a rotor to construct AIE luminogens.
Chemical Communications 02/2013; · 6.17 Impact Factor
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ABSTRACT: A pyridinyl-functionalized tetraphenylethene (Py-TPE) was synthesized and it demonstrated colorimetric and ratiometric fluorescent responses to trivalent metal cations (M(3+), M = Cr, Fe, Al) over a variety of mono- and divalent metal cations.
Chemical Communications 01/2013; · 6.17 Impact Factor
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ABSTRACT: The research on self-healing polymers has been a hot topic. The encapsulated-monomer/catalyst, supramolecular self-assembly, and reversible or dynamic covalent bond formation are the prevailingly adopted strategies. The alternative of irreversible covalent bond formation is, however, to be further developed. In this contribution, self-healing hyperbranched poly(aroyltriazole)s of PI and PII sharing such mechanism were developed. The polymers were synthesized by our developed metal-free click polymerizations of bis(aroylacetylene)s and triazide. They are processible and have excellent film-forming ability. High quality homogeneous films and sticks free from defects could be obtained by casting. The scratched films could be self-repaired upon general heating. The cut films and sticks could be healed by stacking or pressing the halves together at elevated temperature. Thus, these hyperbranched polymers could find broad applications in diverse areas, and our design concept for self-healing materials should be generally applicable to other hyperbranched polymers with reactive groups on their peripheries.
Scientific Reports 01/2013; 3:1093.
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Jingzhi Sun,
Jianli Hua, Anjun Qin,
Mang Wang,
Ben Zhong Tang,
Zhen Li,
Haipeng Xu,
Yongqiang Dong,
Wangzhang Yuan,
Yuguang Ma,
Hai Xu
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ABSTRACT: We demonstrate a concept-proof work of using fluorescence (FL) "turn-on" probes for the discriminatory detection of cysteine (Cys) over homocysteine (Hcy). The fluorogens are provided with aggregation-induced emission (AIE) characteristic and functionalized with two aldehyde-groups (DMTPS-ALD and TPE-ALD). All the detections were carried out in a biocompatible medium (10 mM HEPES buffer and DMSO, pH 7.4). In principle, the formation of thiazinane/thiazolidine through the chemical reaction of aldehydes on the probe molecules and the residue of Cys/Hcy determines the selective recognition of Cys and Hcy over other amino acids and glucose. The FL responses originate from the AIE property of thiazinane/thiazolidine resultants, which have low solubility and precipitate (aggregate) in the detection medium. The discrimination between Cys and Hcy comes from the difference in reaction kinetics of TPE-ALD/DMTPS-ALD with Cys and Hcy, thereby the FL responses show different time courses and intensity enhancement. It is worth noting that TPE-ALD outshined the other two probes in performance with fast response, a high FL enhancement up to 16-fold, high sensitivity, and good specificity and selectivity. Moreover, its FL response threshold at 250 μM is very close to the lower limit of the normal level of Cys in human plasma, which implies that TPE-ALD could be applied as a potential indicator of Cys deficiency.
Chemistry 11/2012; · 5.93 Impact Factor
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ABSTRACT: Perylene bisimide derivatives substituted with one and two tetraphenylethene moieties at 1 and 1,7-postions show distinct optical properties. The former displays characteristic emission features of perylene bisimides in solution and red emission in the aggregate state, while the latter is nonemissive in solution but highly red-emissive in the aggregate state.
Chemical Communications 10/2012; · 6.17 Impact Factor
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ABSTRACT: A new aggregation-induced emission (AIE) compound 1,2-bis[4-(isothiocyanatomethyl)phenyl]-1,2-diphenylethene () was synthesized for use in SDS-PAGE. The molecule is practically nonemissive in solution but becomes highly emissive after reacting with the amine groups of the proteins by either the prestaining or poststaining method. The sensitivity of achieved in the prestaining method is the same as that of Coomassie brilliant blue (CBB), while that observed in the poststaining method is higher than that of CBB. Excellent linear responses with the amount of protein were obtained in both cases. The detection of a mixture of proteins with different molecular weights was successfully achieved.
The Analyst 10/2012; · 4.23 Impact Factor
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ABSTRACT: Tetraphenylethylene (TPE)-substituted poly(allylamine hydrochloride) (PAH-g-TPE) is synthesized by a Schiff base reaction between PAH and TPE-CHO. The PAH-g-TPE forms micelles in water at pH 6, which are further transformed into pure TPE-CHO nanoparticles (NPs) with a diameter of ≈300 nm after incubation in a solution of low pH value. In contrast, only amorphous precipitates are obtained when TPE-CHO methanol solution is incubated in water. The aggregation-induced emission feature of the TPE molecule is completely retained in the TPE NPs, which can be internalized into cells and show blue fluorescence. Formation mechanism of the TPE NPs is proposed by taking into account the guidance effect of linear and charged PAH molecules, and the propeller-stacking manner between the TPE-CHO molecules.
Macromolecular Rapid Communications 07/2012; 33(18):1584-9. · 4.60 Impact Factor
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ABSTRACT: The 1,3-dipolar cycloaddition of azides and active internal alkynes has been well studied, but is rarely utilized as a tool for polymer preparation. In this work, an efficient polymerization route is developed. Polycycloaddition of diazide (4) and bis(benzoylethynyl)-benzenes and -butane (3) at elevated temperature has produced the first examples of soluble 1,4,5-trisubstituted polytriazoles PI with satisfactory molecular weights (M(w) up to 16 400) in excellent yields (up to 98.6%). All the obtained polymers are thermally stable, losing merely 5% of their weights at temperatures higher than 367 °C. They exhibit higher refractive indices than some commercial plastics and can be crosslinked upon UV irradiation to generate a 3D photopattern with high resolution. The metal-free feature of such a methodology offers a facile tool to prepare functional materials free from the contamination of metal species.
Macromolecular Rapid Communications 05/2012; 33(16):1356-61. · 4.60 Impact Factor
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ABSTRACT: It has been difficult to decipher the mechanistic issue whether E/Z isomerization is involved in the aggregation-induced emission (AIE) process of a tetraphenylethene (TPE) derivative, due to the difficulty in the synthesis of its pure E and Z conformers. In this work, pure stereoisomers of a TPE derivative named 1,2-bis{4-[1-(6-phenoxyhexyl)-4-(1,2,3-triazol)yl]phenyl}-1,2-diphenylethene (BPHTATPE) are successfully synthesized. Both isomers show remarkable AIE effect (α(AIE) ≥ 322) and high fluorescence quantum yield in the solid state (Φ(F) 100%). The conformers readily undergo E/Z isomerization upon exposure to a powerful UV light and treatment at a high temperature (>200 °C). Such conformational change, however, is not observed under normal fluorescence spectrum measurement conditions, excluding the involvement of the E/Z isomerization in the AIE process of the TPE-based luminogen. The molecules of (E)-BPHTATPE self-organize into ordered one-dimensional nanostructures such as microfibers and nanorods that show obvious optical waveguide effect. BPHTATPE shows rich chromic effects, including mechano-, piezo-, thermo-, vapo-, and chronochromisms. Its emission peak is bathochromically shifted by simple grinding and pressurization and the spectral change is reversed by fuming with a polar solvent, heating at a high temperature, or storing at room temperature for some time. The multiple chromic processes are all associated with changes in the modes of molecular packing.
Journal of the American Chemical Society 05/2012; 134(24):9956-66. · 9.91 Impact Factor
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ABSTRACT: Fluorescent hyperbranched polymers (FHBPs), which combine the versatile fluorescent property with unique characteristics of
hyperbranched architecture, are desirable candidates for stimulus responsive materials. This review demonstrates the structure
and environment-dependent emission behaviors of a series of FHBPs. AEE active FHBPs showing opposite performance to ACQ effect
are used to sensitively detect explosives and a superamplification effect is found. Specially designed FHBPs can complex with
metal ions, leading to fluorescence turn-off due to complex quenching effect. The protonation of amino-containing FHBPs exhibits
pH-dependent fluorescence responses to solution acidity. Some FHBPs containing responsive moieties are photo- and thermo-sensitive,
and show potential applications as smart materials.
Keywordsfluorescent hyperbranched polymer-explosives and metal ions detection-pH responsive-optical and thermal sensitive
Science China-Chemistry 05/2012; 53(12):2409-2428. · 1.02 Impact Factor
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ABSTRACT: Regioseletive 1,3-dipolar polycycloadditions of 4,4′-isopropylidenediphenyl dipropiolate (1) and tetraphenylethene (TPE)-containing diazides (2) are carried out in polar solvents such as DMF/toluene at a moderate temperature of 100 °C for 6 h, producing poly(aroxycarbonyltriazole)s
(PACTs) P3 with high molecular weights (M
w up to 23900) and regioregularities (F
1,4 up to ∼90%) in high yields (up to ∼99%). These metal-free click polymerizations can propagate smoothly in an open atmosphere
without protection from oxygen and moisture. The obtained polymers are soluble in common organic solvents and thermally stable
at temperatures up to 375 °C. Thanks to their contained TPE moieties, the PACTs show aggregation-induced emission and can
serve as fluorescent chemosensors for superamplified detection of explosives.
Keywordsaggregation-induced emission–metal-free click polymerization–propiolate–chemosensor
Science China-Chemistry 04/2012; 54(4):611-616. · 1.02 Impact Factor
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ABSTRACT: This paper presents a new synthetic route to hyperbranched polymer. An arylene bipropiolate monomer, dimethylmethylenebis(1,4-phenylene)
bipropiolate, was prepared by a one-step esterification reaction of bisphenol A with propiolic acid. Polycyclotrimrtization
of the monomer was effected by reflux in dimethylformamide (DMF), producing a soluble hyperbranched poly(aroxycarbonylphenylene)
in a good yield. The polymer was perfectly branched with a degree of branching of 100%.
Science in China Series B Chemistry 04/2012; 51(8):705-708. · 1.20 Impact Factor
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ABSTRACT: Poly(1-phenyl-1-octyne)s containing different stereogenic and chromophoric pendants {-[(C6H13)C= C(C6H4-p-CO2-R)]
n
-R = [(1S)-endo]-(−)-borneyl (P3), (1R,2S,5R)-(−)-menthyl (P4), -C6H4-p-(1R,2S,5R)-(−)-menthyl (P5), 2-napthyl (P6), 4-biphenylyl (P7)} have been designed and synthesized. The polymers are prepared in moderate
yields by WCl6-Ph4Sn and possess high molecular weights (M
w up to 64000). The structures and properties of the polymers are characterized and evaluated by NMR, TGA, UV, CD, PL, and
EL analyses. All the polymers are thermally stable and their temperatures for 5% weight loss locate in the range of 300 to
416°C under nitrogen. The energy band gaps of all the polymers are ∼3.0 eV. Polymers P4 and P5 show CD absorptions associated
with the helicity of the polymer segments. Excitation of the THF solutions of P3–P7 by UV irradiation gives strong blue lights
of ∼485 nm with quantum yields higher than 20%. The thin films of the polymers also emit in the same spectral region, indicative
of little aggregation-caused quenching of light emission. Multilayer EL devices with a configuration of ITO/Polymer:PVK/BCP/Alq3/LiF/Al are constructed, which emit blue lights of ∼487 nm. The maximum luminance and external quantum efficiency vary with
the pendant groups, with P6 exhibiting the highest external quantum efficiency of 0.16%. The spectra stability of the EL devices
is outstanding and the EL peak maximum experiences little change with the applied voltage.
Keywordschiral-photoluminescence-polyacetylene-electroluminescence-helicity
Science in China Series B Chemistry 04/2012; 52(10):1691-1702. · 1.20 Impact Factor
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ABSTRACT: We report a fluorescence “turn-on” method to detect the critical micelle concentration (CMC) of surfactants. This method works
well for both cationic and anionic surfactants. It employs an unprecedented mechanism (aggregation-induced emission, or AIE)
to determine the CMC values, and the results are consistent with the data obtained by the classical techniques. In addition,
this method renders the convenient detection of the CMC values. Any large and professional instruments are unnecessary, instead,
a portable UV lamp and an ultrasonic generator are enough to carry out the detection in an ordinary laboratory. Considering
that micelles are interesting entities and have found applications in many important fields such as emulsion polymerization,
template of nanosized materials synthesis, controllable drug delivery and macromolecular self-assembling. Our experimental
results may offer a facile, sensitive and promising method to detect the formation of micelles constructed by the new amphiphilic
molecules and macromolecules.
Science in China Series B Chemistry 04/2012; 52(6):755-759. · 1.20 Impact Factor
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ABSTRACT: A facile route for the synthesis of luminescent and light refractive polymers is proposed. Silole-containing diyne and halogenated tetraphenylethene derivatives are synthesized and their coupling reactions furnish poly(arylene ethynylene)s with high molecular weights in high yields. All of the polymers are soluble and film-forming and possess a high thermal stability. They emit strong green lights when their solutions and nanoparticle suspensions are photoexcited. The polymers show high refractive indices with low chromatic dispersions. Their RI values can be modulated and their thin films can be crosslinked using UV irradiation, generating negative photoresist patterns.
Macromolecular Rapid Communications 02/2012; 33(6-7):568-72. · 4.60 Impact Factor
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ABSTRACT: An unexpected recognition of β-cyclodextrin (CD) from α- and γ-CDs was achieved. The emission from a diboronic acid-containing tetraphenylethene (TPEDB) was amplified upon addition of β-CD, whereas there was almost no response for α-, and γ-CDs. TPEDB is proposed to be anchored onto the wide rim of β-CD through the alternative and conceptually new cooperative boronic acid/diol dynamic binding interaction, resulting in the restriction of intramolecular rotations of its phenyl rings.
Chemistry 12/2011; 17(52):14736-40. · 5.93 Impact Factor
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ABSTRACT: The aggregation-induced emission (AIE) of a 1,2-diphenyl-1,2-di(p-tolyl)ethene (TPE) was explored as a novel fluorescence method for probing the assembling/disassembling of amphiphilic molecules. The fluorescence intensity was able to monitor the formation of micelles and determine the critical micelle concentration (CMC) of surfactants. The temperature-dependent micellization of the pharmaceutically important PEO-PPO-PEO copolymer, Pluronic F127, was further studied by using the TPE fluorescence spectrum intensity. Our results showed good agreement with those reported in the literature by using other methods. The special advantage of the AIE probe method was further explored to determine the assembling/disassembling process of the colored amphiphilic molecule, 1-[4-(3-phenylazophenoxy)butyl]triethylamine bromide (AzoC4), whose CMC value has not previously been described. Since the TPE fluorescence signal mainly comes from the aqueous phase, not from the inside of hydrophobic core, it provides a possible platform to study the CMC of those colored surfactants. Based on the novel fluorescence properties of TPE in the aggregated and dispersed states, one can conclude that the TPE method is a promising method for the determination of the CMC and critical micellization temperature (CMT), particularly having a special advantage to determine the assembling/disassembling process of colored amphiphilic molecules.
The Analyst 08/2011; 136(16):3343-8. · 4.23 Impact Factor
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ABSTRACT: Pentafluorophenyl (PFP) ester-functionalized poly(phenylacetylene)s (PPAs, P1, P2, and P3) were designed and synthesized in desirable yields and molecular weight by using organorhodium complexes as catalysts. Furthermore, these PFP-containing PPAs were used as precursors to prepare a series of mono- and dual-functionalized PPAs by the substitution of the activated ester moieties with functional amines. The structures of the PFP-containing PPAs and the derived functional PPAs were characterized by using multiple spectroscopic techniques including GPC, FTIR, 1H NMR, 13C NMR, and 19F NMR. The experimental details and the characterization data demonstrate that activated ester synthetic route to functional PPAs is facile (just stirring the precursor polymer with proper amine(s) at room temperature for hours), efficient (complete transition from ester to amide has been confirmed), and quantitative (the relative content of a specific functionality can be precisely preset by controlling the feed ratio of the functional amines). By reacting three PFP-containing PPAs with chiral amines or with chiral and nonchiral alkyl amines in a step-by-step way, a series of seven different PPAs with asymmetric carbon in the side chains were obtained. CD measurements indicated that the incorporation of chiral amine into polymer side chains induced helicity formation of P1 backbone. P1-C*Ph(L) and P1-C*Ph(D) backbones adopt predominantly right-handed and left-handed helical conformation, respectively. While the flexible spacer between the chiral center and the rigid PPA backbone blocked the induction of main-chain helicity by chiral pendants, thus no CD signals were recorded for P2-C*Ph(L) and P3-C*Ph(L). Substitution of PFP ester with amine-functionalized PEGs transited the hydrophobic PPAs to hydrophilic. All of the PEG-containing PPAs can be dissolved in water and form clear solutions. Meanwhile, all of the aqueous solutions exhibit LCST behavior and the hydrophilic PEG chains and hydrophobic alkyl spacers have positive and negative impact on the cloud point, respectively. Contact angles measurements showed that the length and content of the PEG chains contribute greatly to the hydrophilic property, and the length of the alkyl spacers and the content of the alkyl amine component played a contrary role. By controlling the ratio of the PEGylated and alkyl amines, the amphiphilic property of the PPAs can be well tailored.
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