Owing to the hybrid nature of organic-inorganic composite coatings, when applied, they can combine the merits of both components and thus make such coatings fit a wide range of applications. However, due to the property differences in these composites, the strategy to obtain well dispersed organic-inorganic coatings is not yet straightforward and it is of great importance for their implementation and to obtain advanced properties such as mechanical properties, corrosion-resistance, aging resistance performance, and others. In this regard, still, even the characterization and direct visualization of the making up the organic-inorganic composites are not easy tasks. Herein, a strategy to visual characterize organic-inorganic composite coatings via aggregation-induced emission (AIE) is reported. Briefly, the approach involved first designing and synthesizing a novel water dispersed AIEgen whose AIE effect was systematically analyzed. Then, inorganic Na-montmorillonite (MMT) was introduced to the synthesized AIEgen via the ion exchange method in order to make the inorganic MMT adopt fluorescence properties. The modified MMT fluorescence property was beneficial for the imaging and characterization of the macro-dispersed MMT in the cured coatings. As an essential addition to the study, the responses of the modified MMT cured composite coatings to temperature and corrosive material erosion were studied in detail. An account of the responses demonstrated the possible application of such modified coatings in high-performance smart paints.
Li Weili Yao Wei Tebyetekerwa Mike Tang Ji-Jun Shengyuan Yang 朱美芳 Hu Rong Anjun Qin 唐本忠 Xu Zexiao
Journal of Materials Chemistry C
Luminogens with aggregation-induced emission (AIE) characteristics have attracted much attention because of their broad applications in optoelectronics, bioprobes and environmental monitoring. Herein, two family of luminogens based on phosphindole oxide (PIO) and benzo[b]thiophene S,S-dioxide (BTO) cores and thiophene substituents are prepared and fully characterized. Their structures and optical properties are comparatively investigated by crystallography, spectroscopy, theory calculation, etc. These luminogens with different connection patterns between thiophene and PIO/BTO cores exhibit different torsion angles and thus diverse photophysical properties. The luminogens show faint emissions in dilute solutions but enhanced emissions in the aggregated state, displaying good AIE feature. Reversible photochromism is observed for the luminogens, and the PIO-based luminogens show better photochromism properties than BTO-based ones. The interesting photoluminescence and photochromism properties endow these new luminogens with good potential in optoelectronic devices and molecular switches.
Shijie Zhen Guo Jingjing Luo Wenwen Anjun Qin Zujin Zhao 唐本忠
Journal of Photochemistry and Photobiology A: Chemistry
Development of new polymerizations based on triple-bond building blocks has received considerable research attention, from which polymers with unique structures and advanced functions can be generated. In this review, we summarize the research efforts on using alkynes and nitrogen-containing triple bonds as building blocks to prepare polymers with linear and topological structures since 2010. The metathesis polymerization and polyaddition of mono- and di-substituted acetylenes, the Cu(I)-catalyzed and metal-free azide-alkyne click polymerization, the thiol-yne click polymerization, polycyclotrimerization of diynes, and the polymerizations based on cyanide and isocyanide monomers are discussed in detail. Moreover, the unique stoichiometric imbalanced polymerization based on alkynes is also briefly introduced. The functions and applications of polymers, produced from these developed polymerization reactions, such as aggregation-induced emission, self-healing, fluorescent patterning, liquid crystal, fluorescence sensing, explosive detection, chiral catalysis and gas permeability are also reviewed.
Liu Yong Anjun Qin 唐本忠
Progress in Polymer Science
The study of blood brain barrier (BBB) functions is important for neurological disorder research. However, the lack of suitable tools and methods has hampered the progress of this field. Herein, we present a hybrid nanodot strategy, termed AIE-Gd dots, comprising of a fluorogen with aggregation-induced emission (AIE) characteristics as the core to provide bright and stable fluorescence for optical imaging, and gadolinium (Gd) for accurate quantification of vascular leakage via inductively-coupled plasma mass spectrometry (ICP-MS). In this report, we demonstrate that AIE-Gd dots enable direct visualization of brain vascular networks under resting condition, and that they form localized punctate aggregates and accumulate in the brain tissue during experimental cerebral malaria, indicative of hemorrhage and BBB malfunction. With its superior detection sensitivity and multimodality, we hereby propose that AIE-Gd dots can serve as a better alternative to Evans blue for visualization and quantification of changes in brain barrier functions.
Guangxue Feng Li Jackson L. Yao Claser Carla Balachander Akhila Tan Yoke Cheng Goh Chiching Kwok Immanuel Weng Han Laurent Rénia 唐本忠 Lai guan Ng Bin Liu
Luminogens with aggregation-induced emission characteristics (AIEgens) are intriguing due to its rapid expansion in various high-tech applications. However, there is still in high demand on the development of novel AIEgens with easy preparation and functionalization, stable structures, tunable emissions, and high quantum efficiency. In this contribution, three AIEgens based on diphenyl isoquinolinium (IQ) derivatives are reported. They can be facilely synthesized and possess high structural stability, favorable visible light excitation, large Stokes shifts, high quantum yields, tunable colors, and sufficient two-photon absorption of near-infrared light. Importantly, they exhibit multifunctionalities. They exhibit mechanochromic property, making them capable to be applied for rewritable papers. They can also be applied in mitochondrial imaging with high specificity, cell permeability, brightness, biocompatibility, and photostability. They are promising for the applications in evaluation of mitochondrial membrane potential and image-guided cancer cell ablation. Last, they are able to stain bacteria in a wash-free manner. All these intriguing results suggest such readily accessible and multifunctional diphenyl IQ-based AIEgens provide a new platform for construction of advanced materials for practical applications.
Jiang Meijuan Xinggui Gu Ryan tsz kin Kwok Li Ying Herman ho yung Sung Zheng Xiaoyan Yilin Zhang 林荣业 Ian Williams 黄旭辉 Kam sing Wong 唐本忠
Advanced Functional Materials
Conjugated polymers (CPs) have drawn great attention due to their excellent optical and electronic properties for decades. Among the varieties of CPs, polyacetylenes (PAs) triggered a revolution in polymer science due to their conductivity in highly doped state. Yet, the unstability and unprocessability of the pristine polyacetylene led researchers exploring their derivatives with substituents. Luckily, greatly improved stability and processability have been achieved by poly(disubstituted polyacetylene)s or PDSAs, that show efficient fluorescence emission in both solution and solid state and excellent circular polarized luminescence. This review summarizes recent research regarding PDSAs, beginning with the novel achievements of the discovery of the Pd-based catalyst systems for the polymerization of disubstituted acetylene monomers (DSAms), followed by a description of the effect of polymerization catalysts on the stereochemistry of obtained polymers and the effect of the stereochemistry on functional properties. Then, an updated summary of alternative synthetic routes to PDSAs, that is, post-polymerization modifications is contributed. This strategy has shown strong vitality due to the highly efficient reaction tools furnished by organic chemists such as click chemistry and activated esters. PDSAs usually possess intrinsically porous structure, exhibiting significant and variable fluorescent responses to exotic species such as solvents with different polarities, metal cations and explosives, and these properties indicate that PDSAs are promising candidates for fluorescent sensors and probes. Their reversible responses to applied fields such as stress and fluid gradient allow PDSAs to be active components of actuators. Moreover, due to the unique conjugated polyene main-chain and metathesis polymerization mechanism, PDSAs pronounced chirality transfer capacity and outstanding circular polarized luminescent property. Finally, an outlook of the application and suggestions of the synthetic efforts are forwarded.
Wang Xiao Jingzhi Sun 唐本忠
Progress in Polymer Science
Two novel AIE-active salicylaldehyde azine (SAA) derivatives with a typical excited-state intramolecular proton transfer (ESIPT) process are prepared by introducing electron-withdrawing and donating groups at para-position of phenolic hydroxyl group (CN-SAA and TPA-SAA). The effect of the proton activity in SAA framework on their optical behaviors is investigated spectroscopically. The results from NMR and solvation measurements show that the proton of phenolic hydroxyl group has higher activity when there are electron-withdrawing groups, and the absorption and fluorescence spectra in buffers with different pH also provide the same results. After inviting F as a nucleophilic probe, this proton activity difference in CN-SAA and TPA-SAA becomes more obvious. The potential application of both molecules is investigated. TPA-SAA exhibits good quantitative sensing ability towards F with a fluorescence “turn-on” mode, whereas the aggregates of TPA-SAA can selectively and sensitively detect Cu in aqueous solution. From these results, a structure-property relationship is established: the occurrence of ESIPT process will become much easier when linking electron-withdrawing groups at the para-position of phenolic hydroxyl group (e.g., CN-SAA), and it is better to introduce electron-donating groups to enhance the sensing ability towards ions (e.g., TPA-SAA). This work will provide guidance for further design and preparation of AIE-active luminogens with ESIPT process for sensing applications.
Wang Zhiming Zhou Fan Wang Jing Zujin Zhao Anjun Qin Zhenqiang Yu 唐本忠
Science China Chemistry
Development of new aggregation-induced emission (AIE) luminogens has been a hot research topic because they thoroughly solve the notorious aggregation-caused quenching effect confronted in conventional fluorogens and their promising applications in, for example, organic light-emitting diodes, chemo- and biosensors and bioimaging. Many AIE luminogens (AIEgens) have been prepared but most of them are silole, tetraphenylethene, distyrylanthracene, and their derivatives. In this work, based on the skeleton of tetraphenylpyrazine (TPP), a new AIEgen, named TPP-PDCV, is generated by functionalizing TPP with malonitrile group. TPP-PDCV can serve as a sensitive ratiometric fluorescent probe for detecting hydrogen sulfide with high speciality and low detection limit of down to 0.5 × 10m. The mechanism for such detection is fully investigated and deciphered. Unlike most reported mechanochromic AIEgens, which undergo turn-off or -on emission or emission bathochromic shift in the presence of external stimuli, TPP-PDCV exhibits an abnormal and reversible mechanochromism with hypsochromic effect. These indicate that TPP-PDCV possesses a huge potential for high-tech applications through rational modification of TPP core.
Chen Ming Chen Rui Shi Yang Wang Jianguo Cheng Yanhua Li Ying Gao Xuedong Yun Yan Jingzhi Sun Anjun Qin Ryan tsz kin Kwok 林荣业 唐本忠
Advanced Functional Materials
In the text, two luminescent materials ECPPTT and ECDPTT, have been designed and synthesized by integrating tetraphenyl/triphenyl-ethene(TPE/TrPE), carbazole group and thianthrene-9,9,10,10-tetraoxide unit. ECPPTT and ECDPTT possess obvious AIE and TADF capabilities, and show good thermal stability in their thin film of 240 °C and 262 °C, respectively. Non-doped organic light emitting diodes(OLED) using ECPPTT and ECDPTT as emission layer are prepared and exhibit blue-green and green emission color with peaks at 494, 517 nm, respectively. The non-doped OLED based on ECPPTT provides good peak EL efficiencies of 3.437 cdA and 10090cdm; while non-doped OLED fabricated with ECDPTT affords a maximum current efficiency and a maximum luminance of 2.478 cdA and 7561cdm. These results have demonstrated the feasibility of combing AIE and TADF units to design new molecules.
Dong Xiuqing Wang Shujuan Gui Chen Heping Shi Fangqin Cheng 唐本忠
Fixing carbon dioxide (CO) into useful polymeric materials has attracted broad interest since carbon dioxide is an abundant, inexpensive, nontoxic, and renewable C1 resource. Nevertheless, the polymerization of CO and alkynes attracted less attention because the propagation step involving CO is a major obstacle. Herein, we overcome this obstacle by developing a facile and efficient AgWO-catalyzed polymerization of CO, diynes, and alkyl dihalides under mild reaction conditions. Soluble and thermally stable poly(alkynoate)s with high weight-average molecular weights (up to 31 400) were obtained in high yields (up to 95%). Thanks to its unique reaction mechanism, this step-growth polymerization can produce an ethynyl group terminated telechelic polymer that can be used as macromonomer to prepare poly(alkynoate)s with higher molecular weights by either continually adding alkyl dihalide into the reaction solution or mixing the isolated telechelic polymers with alkyl dihalide and catalytic system under a CO atmosphere. The resultant polymers show versatile properties. The tetraphenylethene, silole, and tetraphenylpyrazine moieties that feature the aggregation-induced emission (AIE) characteristics can be facilely incorporated into the polymer main chains to make them AIE active with high absolute quantum yields up to 61% in the film state. Their containing ester linkages endow the polymers degradable under basic conditions, and the alkynoate repeating units enable them to be postfunctionalized by the powerful amino-yne click reaction to generate nitrogen-containing stereo- and regioregular polymers with unity grafting ratio. Thus, this work not only establishes a powerful polymerization to directly fix CO but also provides poly(alkynoate)s with versatile properties.
Song Bo Benzhao He Anjun Qin 唐本忠