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%.

Cathy K.W. Jim;Anjun Qin;Jacky W.Y. Lam;Jianzhao Liu;Matthias Haeussler;本忠 唐

Science in China, Series B: Chemistry

2008-8

In this work, we report a new blue AIEgen, (9,9-dimethyl-7-(4-(1,2,2-triphenylvinyl)phenyl)-9H-fluoren-2-yl)dimesitylborane (TPE-FB), composed of dimesitylboryl, fluorene and tetraphenylethene (TPE) groups. The thermal stability, electronic structure, optical properties, transient fluorescence decay and electroluminescence of TPE-FB are studied. TPE-FB shows high thermal stability and good aggregation-induced emission (AIE) properties. Due to the presence of the dimesitylboryl group, TPE-FB can interact with fluorine ions to cause a blue-shift in the absorption spectrum and an apparent decrease in the emission spectrum. TPE-FB also exhibits mechanochromic properties, and the fluorescence color of its solid can be reversibly switched between blue and sky-blue by simple grinding and heating (fuming). TPE-FB can function as a light-emitting layer in nondoped sky-blue OLEDs with good performances.

Yinghao Li;Zeyan Zhuang;Gengwei Lin;Zhiming Wang;Pingchuan Shen;Yi Xiong;Bohan Wang;Shuming Chen;Zujin Zhao;本忠 唐

New Journal of Chemistry

2018

The discovery of the photophysical phenomenon of aggregation-induced emission (AIE) by Tang in 2001 has drawn intense attention of scientists all over the world and created potential applications in various areas, such as biological probes, chemical sensors, and optoelectronic devices. Incorporation of AIE with chirality is a pioneering attempt to broaden the field of AIE research. Generally, chiral AIEgens are designed by attaching chiral units to an AIE-active building block. From another point of view, AIEgens with molecular rotors or vibrators are a kind of latent chiral molecule, whose chirality can be detected at a specific state by breaking the mirror symmetry. Aggregation as a bridge tethers molecular AIEgens and their macroscopic self-assembly. Through precise control of the chirality, well-defined helical architectures with amplified chiral signals are formed. In contrast to circularly-polarized luminescence at the molecular level, these aggregates with ordered packing always show enhanced performance in emission efficiency and dissymmetry factor.

Hai Tao Feng;Chenchen Liu;Qiyao Li;Haoke Zhang;Jacky W.Y. Lam;本忠 唐

ACS Materials Letters

2019-7-1

The luminescent liquid crystals (LLCs) are expected to solve the conflicts between the aggregation caused quenching and the requirement of aggregation or self-organization for LCs. Herein, we developed a new strategy of applying aggregation-induced emission (AIE) phenomenon to the molecular design of LCs towards LLCs. In this report, a calamitic liquid crystal based on tolane with AIE characteristics was successfully synthesized and the chemical structure was characterized by ¹H, ¹³C NMR, and matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) high-resolution mass spectra. The fluorescence behavior was studied by fluorescence spectroscopy and the liquid crystal phase behaviors were investigated by differential scanning calorimetry (DSC), polarized optical microscopy (POM). The crystal structure was obtained by X-ray diffraction crystallography with P1 space group. Results demonstrated that the sample was AIE active and the LC phases sequence during cooling was nematic, smectic C and smectic B phase.

Yafei Chen;Jiesheng Lin;Wangzhang Yuan;Zhenqiang Yu;Jacky Wingyip Lam;本忠 唐

Science China Chemistry

2013-9

In this Letter, the photoluminescence of 1,1,2,3,4,5-hexaphenylsilole (HPS) and poly{1,1-[(1,2,3,4,5-pentaphenylsiloly)oxy]-1-phenyl-1-undecyne} (PS9PA) was studied in detail by time-resolved fluorescence technique to investigate possible mechanisms of their unique aggregation-induced emissions. Enhanced emissions and long lifetimes of HPS and PS9PA films were detected in PMMA matrix compared to those of their solutions. Furthermore, strong fluorescence with nanosecond lifetimes was also obtained in the single crystal of HPS. These results show that intramolecular vibrational and torsional motions can act as efficient nonradiative pathways for the excited states to decay in the solutions and that suppression of these motions by restricting intramolecular vibrations in the solid state leads to enhanced fluorescence.

Yan Ren;Yongqiang Dong;Jacky W.Y. Lam;本忠 唐;Kam Sing Wong

Chemical Physics Letters

2005-2-4

Synthesis of nitrogen-containing polymers has always been a hot research topic for their broad applications as functional materials. In this work, we established new, spontaneous, and atom-economic amino-yne click polymerization for the construction of regio-/stereoregular nitrogen-containing polymers. Aroylacetylenes, which could be facilely prepared without using water-sensitive ethynylmagnesium bromide and harsh reaction conditions, could be polymerized with amines in the absence of any catalyst under ambient conditions, and poly(β-enaminone)s with high weight-average molecular weights (M_w of up to 49 400) could be produced in excellent yields (up to 99%). Moreover, sole E-isomer-containing polymers could be obtained efficiently from the click polymerization of aroylacetylenes and secondary amines, whereas absolute Z-configuration products were prepared when using primary amines. In addition, poly(β-enaminone)s could be degraded upon the addition of Lewis acid and primary amines in aqueous solution and definite compounds could be generated, proving their wide application prospects as degradable nitrogen-containing polymers.

Xu Chen;Tianwen Bai;Rong Hu;Bo Song;Lin Lu;Jun Ling;Anjun Qin;本忠 唐

Macromolecules

2020-4-14

Polymeric materials are susceptible to the chain re-conformation, reorientation, slippage, and bond cleavage upon mechanical stimuli, which are likely to further grow into macro-damages and eventually lead to the compromise or loss of materials performance. Therefore, it is of great academic importance and practical significance to sensitively detect the local mechanical states in polymers and monitor the dynamic variations in polymer structures and properties under external forces. Mechanochromic fluorescent polymers (MFP) are a class of smart materials by utilizing sensitive fluorescent motifs to detect polymer chain events upon mechanical stimuli. Taking advantage of the unique aggregation-induced emission (AIE) effect, a variety of MFP systems that can self-report their mechanical states and mechano-induced structural and property changes through fluorescence signals have been developed. In this feature article, an overview of the recent progress on MFP systems enabled by AIE process is presented. The main design principles, including physically doping dispersed or microencapsulated AIE luminogens (AIEgens) into polymer matrix, chemically linking AIEgens in polymer backbones, and utilizing the clusterization-triggered emission of polymers containing nonconventional luminogens, are discussed with representative examples. Perspectives on the existing challenges and problems in this field are also discussed to guide future development.

Ting Han;Lijie Liu;Dong Wang;Jinglei Yang;本忠 唐

Macromolecular Rapid Communications

2020

Robust luminescent dyes with efficient two-photon fluorescence are highly desirable for biological imaging applications, but those suitable for organic dots fabrication are still rare because of aggregation-caused quenching. In this work, a red fluorescent silole, 2,5-bis[5-(dimesitylboranyl)thiophen-2-yl]-1-methyl-1,3,4-triphenylsilole ((MesB)₂DTTPS), is synthesized and characterized. (MesB)₂DTTPS exhibits enhanced fluorescence efficiency in nanoaggregates, indicative of aggregation-enhanced emission (AEE). The organic dots fabricated by encapsulating (MesB)₂DTTPS within lipid-PEG show red fluorescence peaking at 598 nm and a high fluorescence quantum yield of 32%. Upon excitation at 820 nm, the dots show a large two-photon absorption cross section of 3.43 × 10⁵ GM, which yields a two-photon action cross section of 1.09 × 10⁵ GM. These (MesB)₂DTTPS dots show good biocompatibility and are successfully applied to one-photon and two-photon fluorescence imaging of MCF-7 cells and two-photon in vivo visualization of the blood vascular of mouse muscle in a high-contrast and noninvasive manner. Moreover, the 3D blood vasculature located at the mouse ear skin with a depth of over 100 μm can also be visualized clearly, providing the spatiotemporal information about the whole blood vascular network.

Bin Chen;Guangxue Feng;Bairong He;Chiching Goh;Shidang Xu;Gabriel Ramos-Ortiz;Laura Aparicio-Ixta;Jian Zhou;Laiguan Ng;Zujin Zhao;Bin Liu;本忠 唐

Small

2016-2-10

A simple approach to decorate carbon nanotube (CNT) with silver nanoparticles (Ag-NPs) was developed to enhance the electrical conductivity of CNT. CNTs were functionalized using ball milling in the presence of ammonium bicarbonate, followed by reduction of silver ions in N, N-dimethylformamide, producing silver decorated CNTs (Ag@CNTs). The Ag@CNTs were employed as conducting filler in epoxy resin to fabricate electrically conducting polymer composites. The electrical, thermal and mechanical properties of the composites were measured and compared with those containing pristine and functionalized CNTs. It was found that when pH was about six, highly dispersed Ag-NPs can be decorated on functionalized CNTs. The electrical conductivity of composites containing 0.10 wt% of Ag@CNTs was more than four orders of magnitude higher than those containing same content of pristine and functionalized CNTs, confirming the advantage of the Ag@CNTs as effective conducting filler. The ameliorating effect of improved electrical conductivity was not at the expense of thermal or mechanical properties.

鹏程 马;本忠 唐;Jang Kyo Kim

Carbon

2008-9

A 3-silolene derivative, 2,2,5,5-tetrakis(dimethylsilyl)-1,1-dimethyl-3,4- diphenyl-3-silolene (TDMSHS), is first synthesized and characterized by X-ray diffraction crystallography and spectroscopic methods. Hydrosilylation polymerization of TDMSHS with 1,1-dimethyl-2,5-bis(4-ethynylphenyl)-3,4- diphenylsilole in the presence of Karstedt's catalyst generates a stereoregular silole-containing hyperbranched poly(silylenevinylene) (hb-SPSV) with a high molecular weight (̄M _w = 146000, ̄M _w/̄M _n 1.5) in high yield (≈95%). hb-SPSV exhibits excellent thermal stability and strong fluorescence, and the emission of its aggregates in aqueous mixture can be quenched efficiently by picric acid with large quenching constants K _SV up to 414400 M ^-1. A fully substituted 3-silolene bearing four dimethylsilyl groups is first synthesized, whose hydrosilylation with diethynylsilole in the presence of Karstedt's catalyst generates a stereoregular silole-containing hyperbranched poly(silylenevinylene) in high yield, with excellent thermal stability, strong fluorescence, and sensitive response to explosives.

Zujin Zhao;Yanju Guo;Tao Jiang;Zhengfeng Chang;Jacky W.Y. Lam;Liwen Xu;Huayu Qiu;本忠 唐

Macromolecular Rapid Communications

2012-6-27