Tetra(4-(diethylamino)phenyl)ethene (TPE-4N), a new derivative of tetraphenylethene (TPE), is facilely prepared in one step from bis(4-(diethylamino)phenyl)methanone in a good yield of 85%. TPE-4N shows aggregation-induced emission (AIE) with high solid-state fluorescence quantum yields up to 63.5%. It has strong proton capture capability, allowing for reversible fluorescence switching in acidic and basic solutions. A good linear relationship between the emission intensity and the pH value ranging from 4.4 to 6.0 is established. By exposing to hydrochloride vapor, the color of TPE-4N powder is changed from yellow-green to white, accompanied by a fluorescence color change from green to sky-blue. The resulting protonated luminogen (p-TPE-4N) can be readily reverted to TPE-4N by fuming with hot triethylamine vapor. The protonation and deprotonation processes are reversible and can be repeated many times without fatigue in the solid state. In addition, p-TPE-4N exhibits reversible thermochromism between 80-120 °C, and reverts to TPE-4N by heating up to 120 °C. Multiple stimuli-responsiveness and reversible fluorescence indicate that TPE-4N is a promising candidate for chemical sensing and environmental monitoring.

Zhiming Wang;Han Nie;Zhenqiang Yu;Anjun Qin;Zujin Zhao;本忠 唐

Journal of Materials Chemistry C

2015-8-4

PMMA films containing tetraphenylethylene (TPE) derivatives as red-emissive AIE fluorophores (AIEgen) were demonstrated to be sensitive to both volatile organic compounds (VOCs) and thermal stress. Notably, a novel AIE fluorophore (TPE_RED) was synthesized and used as the initiator to prepare red-emitting poly(methyl methacrylate) polymers (PMMA_TPE_RED1.5) via atom transfer radical polymerization (ATRP). The sensing performances of the spin-coated films (thickness of 2 μm) demonstrated significant vapochromism when exposed to VOCs characterized by high vapour pressure and favourable interaction with the polymer matrix. It was worth noting that PMMA_TPE_RED1.5 displayed substantial vapochromism already at concentration of CHCl3 vapours of 40 ppm, which is about four times smaller than those ever registered in our laboratory with the same apparatus. This threshold was even more decreased in the case of PMMA films containing the TPE_RED physically mixed or another TPE-based derivative already tested in literature, i.e., the barbituric acid-functionalized tetraphenylethene derivative (TPE-HPh-Bar). PMMA films containing TPE_RED AIEgen resulted also sensitive to temperature variations showing an evident thermochromic response close to the glass transition temperature of the polymer matrix.

Nicola Guidugli;Riccardo Mori;Fabio Bellina;本忠 唐;Andrea Pucci

2018-10-9

In this work, a benzothiazole-based aggregation-induced emission luminogen (AIEgen) of 2-(5-(4-carboxyphenyl)-2-hydroxyphenyl)benzothiazole (3) was designed and synthesized, which exhibited multifluorescence emissions in different dispersed or aggregated states based on tunable excited-state intramolecular proton transfer (ESIPT) and restricted intramolecular rotation (RIR) processes. 3 was successfully used as a ratiometric fluorescent chemosensor for the detection of pH, which exhibited reversible acid/base-switched yellow/cyan emission transition. More importantly, the pH jump of 3 was very precipitous from 7.0 to 8.0 with a midpoint of 7.5, which was well matched with the physiological pH. This feature makes 3 very suitable for the highly sensitive detection of pH fluctuation in biosamples and neutral water samples. 3 was also successfully used as a ratiometric fluorescence chemosensor for the detection of acidic and basic organic vapors in test papers.

Kai Li;Qi Feng;Guangle Niu;Weijie Zhang;Yuanyuan Li;Miaomiao Kang;Kui Xu;Juan He;红卫 侯;本忠 唐

ACS Sensors

2018-5-25

Cyclotrimerization of alkynes to aromatics represents a promising approach to two-dimensional conjugated networks due to its single-reactant and atom-economy attributes, in comparison with other multicomponent coupling reactions. However, the reaction mechanism of alkyne cyclotrimerization has not yet been well understood due to characterization challenges. In this work, we take a surface reaction approach to study fundamental polymerization mechanism by using a diyne monomer named 4,4′-diethynyl-1,1′-biphenyl as a test bed. We have succeeded in directly characterizing reactants, intermediates, and their reaction products with the aid of scanning tunneling microscope, which allows us to gain mechanistic insights into the reaction pathways. By combining with density functional theory calculation, our result has revealed for the first time that the polycyclotrimerization is a two-step [2+2+2] cyclization reaction. This work provides an in-depth understanding of polycyclotrimerization process at the atomic level, offering a new avenue to design and construct of single-atom-thick conjugated networks.

Haitao Zhou;Jianzhao Liu;Shixuan Du;Lizhi Zhang;Geng Li;Yi Zhang;本忠 唐;鸿钧 高

Journal of the American Chemical Society

2014-4-16

Luminescent polymers are referred to as conjugated polymers, which are constructed by -aromatic building blocks functioning as emitting units. But in recent years, it has been found that a few kinds of polymers only containing auxochromophores or unconventional chromophores such as aliphatic tertiary amine, carbonyl, ester, and amide demonstrate strong luminescence under proper conditions. Poly(amido amine) (PAMAM) dendrimers and hyperbranched poly(amido amine)s are the first reported and most investigated luminescent polymers containing unconventional chromophores. Lately, this kind of polymers have been extended to hyperbranched poly(amino ester)s (hb-PAEs), hyperbranched poly(ether amide)s (hb-PEAs), and polyurea dendrimers (PUREs) containing tertiary amine moieties. The luminogen of PAMAMs, hb-PAEs, hb-PEAs and PUREs is associated with the N-branched tertiary amine moiety and the oxidation of the tertiary amine is assigned to the emitting source. Meanwhile, some distinct polymers had been also reported to be luminescent. Poly[(maleic anhydride)-alt-(vinyl acetate)], polyisobutene succinic anhydrides, glycodynamer analogues of poly(acrylhydrazone)s and multiblock polymer derived by poly(trithiocarbonate) mediated reversible addition-fragmentation chain transfer (RAFT) polymerization of N-isopropyl-acrylamide. A common feature of these polymers is that only carbonyl and ester groups rather than tertiary amine are involved in the polymer structure. Aggregation of multiple carbonyl groups induced emission is usually adopted to explain the mechanism of the emission, and the interaction between carbonyl and phenyl groups was also used to explain the unconventional emission.

Tian Huang;Zhaoyang Wang;Anjun Qin;Jing Zhi Sun;本忠 唐

Acta Chimica Sinica

2013-7

Luminogenic molecules with aggregation-induced emission (AIE) property are free of aggregation-caused quenching and thus have great potential in the fabrication of efficient non-doped OLEDs. Herein, a series of new carbazole-substituted siloles have been synthesized and characterized. Their crystal and electronic structures, thermal stabilities, electrochemical behaviors, and photophysical properties are thoroughly investigated. These silole derivatives exhibit prominent AIE characteristics with high emission efficiencies in solid films. They can function as light-emitting layers in non-doped OLEDs, affording eminent electroluminescence efficiencies of 17.59 cd/A, 12.55 lm/W and 5.63%, amongst the most efficient non-doped OLEDs based on fluorescent emitters, indicating their promising applications in OLEDs.

Yi Xiong;Jiajie Zeng;Bin Chen;Jacky W.Y. Lam;Zujin Zhao;Shuming Chen;本忠 唐

Chinese Chemical Letters

2019-3

The marriage of reflected light originating from photonic crystals (PCs) and emitted light would create miraculous phenomena. However, traditional luminophores cannot avoid the problem of aggregation-caused quenching. To solve this problem, we develop a general method to incorporate aggregation-induced emission luminogens (AIEgens) into PCs via physical absorption or chemical reaction. The resulting luminescent PCs display diverse structural colors in response to water stimulation, due to the swelling of the aqueous medium. Such a water-tunable photonic band gap red-shift has the ability to modulate the AIEgen emission, as well as narrowing its full width at half maximum (FWHM), which allows the luminescent PC to behave as a smart intramolecular filter that is capable of creating arbitrary light from only one material. In addition, the filter is believed to modulate the broad emission spectra of AIEgens arising from different conformations. Furthermore, the luminescent PC can respond to ethanol stimulation due to two factors: (a) swelling of the aqueous medium (external tuning); and (b) expansion of nanoparticles (internal tuning). By exploiting the synergy of the external-internal tuning, the emission wavelength and intensity can be finely changed. Both the water- and ethanol-tunable emission shift fit to a linear relationship, and thus the luminescent PC could be able to quantitatively detect humidity in the environment and alcohol in wine.

Hong Wang;Xinggui Gu;Rongrong Hu;Jacky W.Y. Lam;德清 张;本忠 唐

Chemical Science

2016

Aggregation-induced delayed fluorescence (AIDF) can be regarded as a special case of aggregation-induced emission (AIE). Luminogens with AIDF can simultaneously emit strongly in solid state and fully utilize the singlet and triplet excitons in organic light-emitting diodes (OLEDs). In this work, two new AIDF luminogens, DMF-BP-DMAC and DPF-BP-DMAC, with an asymmetric D–A–D′ structure, are designed and synthesized. The characteristics of both luminogens are systematically investigated, including single crystal structures, theoretical calculations, photophysical properties and thermal stabilities. Inspired by their AIDF nature, the green-emission non-doped OLEDs based on them are fabricated, which afford good electroluminescence performances, with low turn-on voltages of 2.8 V, high luminance of 52560 cd m ⁻² , high efficiencies of up to 14.4 %, 42.3 cd A ⁻¹ and 30.2 lm W ⁻¹ , and very small efficiency roll-off. The results strongly indicate the bright future of non-doped OLEDs on the basis of robust AIDF luminogens.

Jiajie Zeng;Jingjing Guo;Hao Liu;Jacky W.Y. Lam;Zujin Zhao;Shuming Chen;本忠 唐

Chemistry - An Asian Journal

2019-3-15

The rational design of effective tools capable of monitoring hydrogen sulfide (H₂S) is of great importance to fully understand its physiological and pathological functions. Herein, a self-assembled fluorescent nanoprobe with both aggregation-induced emission (AIE) and excited-state intramolecular proton transfer (ESIPT) characteristics for H₂S detection has been successfully developed via a modified nanoprecipitation method. The nanoprobe features high water dispersibility, a large Stokes shift (ca. 100 nm), good biocompatibility as well as high selectivity towards H₂S over other putative interferents. Live cell imaging experiments demonstrate that the nanoprobe, with good cell-membrane permeability, can facilitate the visualization of exogenous and endogenous H₂S levels. Moreover, the nanoprobe has also been found capable of detecting H₂S in zebrafish. This nanoprobe with AIE and ESIPT characteristics can provide a novel method for the development of fluorescent probes for monitoring biological processes.

Peisheng Zhang;Xuezheng Nie;Meng Gao;钫 曾;Anjun Qin;水珠 吴;本忠 唐

Materials Chemistry Frontiers

2017-5

Light emission of a hyperbranched poly(silylenephenylene) is quenched exponentially by picric acid, with quenching constant up to ∼1.5 × 10⁵ L mol^-1. This superamplification effect makes the polymer a highly sensitive chemosensor for explosive detection.

Jianzhao Liu;Yongchun Zhong;Ping Lu;Yuning Hong;Jacky W.Y. Lam;Mahtab Faisal;Yong Yu;Kam Sing Wong;本忠 唐

Polymer Chemistry

2010-6