Efficient room temperature phosphorescence is observed in natural compounds and polymers such as starch, cellulose, bovine serum albumin (BSA), and some other carbohydrates. Whereas being practically nonluminescent in solutions and TLC plates, they emit bright phosphorescence in the crystalline states with lifetime up to microseconds, exhibiting crystallization-induced phosphorescence (CIP) characteristics. The CIP of these natural products without any conventional chromophores offers a new platform for the exploration of conceptually novel luminogens.

Yongyang Gong;Yeqiang Tan;Ju Mei;Yiren Zhang;Wangzhang Yuan;永明 张;Jingzhi Sun;本忠 唐

Science China Chemistry

2013-9

A versatile process employing anionic surfactants has been developed for the preparation of processible nanocomposite films with electrical conductivity and magnetic susceptibility. Maghemite (g-Fe₂O₃) nanoclusters (∼10 nm in size) are coated with 4-dodecyl-benzenesulfonic acid, and polyaniline (PAn) chains are doped with 10-camphorsulfonic acid. The coated nanoclusters and doped polymers are soluble in common solvents, and casting the solutions readily gives free-standing nanocomposite films with nanocluster contents as high as ∼50 wt %. The g-Fe₂O₃/PAn nanocomposites show high conductivity (82-237 S cm^-1) and magnetizability (up to ∼35 emu/g g-Fe₂O₃).

本忠 唐;Yanhou Geng;Qunhui Sun;Xi Xiang Zhang;遐斌 景

Pure and Applied Chemistry

2000

Debate on the origin of chirality has lasted for several centuries. Lots of theories in different fields have been propounded to illustrate the possible sources. However, there were no convincing proofs could be provided. In this work, through constructing the relationship between aggregation and chirality, a significant insight was brought to explain how the chirality was generated from the achiral system. Besides, aggregation-induced circular dichroism (AICD) effect was discovered in some AIEgens decorated with amino acid or sugars and aggregation-annihilated circular dichroism (AACD) effect was reported in axially chiral systems. In AICD systems, it was proved that the chirality could transfer from chiral centers to AIEgens in the aggregate state but not solution. Meanwhile, it was concluded that the right-handed helical structures corresponded to a negative Cotton effect and vice versa. For the AACD effect, further studies suggested that the annihilation was caused by the change of twist angle within the process of aggregation.

Haoke Zhang;Ryan T.K. Kwok;Jacky W.Y. Lam;本忠 唐

2018

Hyperbranched polymers constructed from CO₂ possess unique architectures and properties; however, they are difficult to prepare. In this work, CO₂-based, hyperbranched poly(alkynoate)s (hb-PAs) with high molecular weights and degrees of branching are facilely prepared under atmospheric pressure in only 3 h. Because hb-PAs possess two types of ethynyl groups with different reactivities, they can undergo site-selective, three-step functionalizations with nearly 100% conversion in each step. Taking advantage of this unique feature, functional hb-PAs with versatile properties are constructed that could be selectively tailored to contain hydrophilic oligo(ethylene glycol) chains in their branched chains, on their periphery, or both via tandem polymerizations. Hyperbranched polyprodrug amphiphiles with high drug loading content (44.3 wt%) are also generated, along with an artificial light-harvesting system with high energy transfer efficiency (up to 92%) and white-light-emitting polymers. This work not only provides an efficient pathway to convert CO₂ into hyperbranched polymers, but also offers an effective platform for site-selective multistep functionalizations toward functional polymeric materials.

Bo Song;Rongyuan Zhang;Rong Hu;Xu Chen;Dongming Liu;Jiali Guo;Xiaotian Xu;Anjun Qin;本忠 唐

Advanced Science

2020-9-1

Phase structures and transitions of a series of biphenyl containing side-chain liquid crystalline polyacetylenes (SCLCPAs) with different length of spacer and alkyl tail, poly((m + 2)-{[(4′-alkyloxy-4-biphenylyl)carbonyl]oxy}-1-yne) [P-m,7 (m = 4, 5, 8), P-m,5 (m = 9), P-m,5^L (m = 3, 9), m is the number of methylene units in the spacer], were studied by differential scanning calorimeter, polarized light microscopy, one- and two-dimensional wide-angle X-ray diffraction. It is revealed that phase structures of the samples are strongly dependent on the lengths of spacer and alkyl tail. The samples with short spacer (m ≤ 4) render the molecular shape of sheet-like due to the strong coupling between the backbone and the biphenyl groups on side-chains. They form highly ordered smectic phase with an additional ordering on the subnanometer scale (SmX^o) at low temperatures. For m > 5, P-m,7 exhibits the low-temperature phase of smectic B (SmB), while P-9,5 and P-9,5^L form smectic E (SmE). As the long spacers adopt more gauche conformations to satisfy the ordered packing of biphenyl groups, the coupling of main- and side-chain is relieved. Among the samples studied, P-5,7 is unique, which can retain the sheet-like shape but form the SmB structure based on a fully interdigitated packing manner. Therefore, the spacer length of m = 5 sets the boundary between coupling and decoupling of the backbone and side-chains. Phase transition sequences of the SCLCPAs studied are also found to be influenced clearly by varying the spacer and tail lengths.

Zhen Qiang Yu;Ting Ting Li;Zhe Zhang;Jia Hao Liu;Wang Zhang Yuan;Jacky W.Y. Lam;Shuang Yang;Er Qiang Chen;本忠 唐

Macromolecules

2015-5-12

Most of the existing metal carbonyl catalysts for acetylene polymerizations need to be preactivated by chlorine-containing additives or by UV irradiation in halogenated solvents. In this work, we developed a series of `simple' metal carbonyl catalysts of general structure M(CO)_xL_y (M = Mo, W), none of which require additives or pre-photoirradiation, most of which are air- and moisture-stable, and some of which work well in nonhalogenated solvents. The acetonitrile complexes M(CO)₃(NCCH₃)₃ initiated polymerizations of a variety of mono- and disubstituted acetylenes at room temperature. The arene and diene complexes W(CO)₃(mes) and Mo(CO)₃(nbd) (mes = mesitylene, nbd = 2,5-norbornadiene) are tolerant of polar groups and effected polymerizations of functional acetylenes containing ester, ether, and cyano groups. The halogenated complexes MI₂(CO)₃(NCCH₃)₂ catalyzed polymerizations of phenylacetylene in toluene. The chlorine-containing acetylene monomers ClC triple bond CC₆H₅ and ClC triple bond CC₆H₁₃ were readily polymerized by the Mo complexes in nonhalogenated solvents such as toluene and dioxane, giving polymers with high molecular weights (M_w up to 883×10³) in high yields (up to 100%).

Kaitian Xu;Han Peng;Jacky Wing Yip Lam;Tommy Wan Hong Poon;Yuping Dong;洪耀 徐;Qunhui Sun;Kevin Ka Leung Cheuk;Fouad Salhi;Priscilla Pui Sze Lee;本忠 唐

Macromolecules

2000-9-19

OLEDs with high efficiency and low roll-off are urgently needed to meet the constantly increasing commercial demands for white organic light-emitting diodes (WOLEDs) in lighting industry applications. To enhance efficiency and decrease WOLED roll-off, complicated doping technologies are employed, which result in an additional increase in costs. Herein, a deep-blue-light molecule (3TPA-CN) with aggregation-induced emission (AIE) is introduced as blue emitter and phosphor host to fabricate WOLEDs. By optimizing the emission zones, high efficiency and low roll-off hybrid WOLEDs are achieved. The maximum forward-viewing power and external quantum efficiencies reach 86.7 lm W ⁻¹ and 22.3%, and remain 59.2 lm W ⁻¹ and 19.6% at a luminance of 1000 cd m ⁻² , fully exhibiting the prospect of AIE molecules as a promising electroluminescence material for the fabrication of high-performance WOLEDs.

Zeng Xu;Yanbin Gong;Yanfeng Dai;Qian Sun;Xianfeng Qiao;Dezhi Yang;Xuejun Zhan;Zhen Li;本忠 唐;Dongge Ma

Advanced Optical Materials

2019-5-3

Integrated diagnosis and therapy systems that can offer traceable cancer therapy are in high demand for personalized medicine. Herein, a pH-responsive polymeric probe containing tetraphenylsilole (TPS) with aggregation-induced emission characteristics and pheophorbide A (PheA) photosensitizer (PS) with aggregation-caused quenching property for tracing the whole process of cancer therapy is reported. At physiological conditions (pH 7.4), the probe self-assembles into nanoparticles (NPs), which show weak fluorescence of PheA with low phototoxicity, but strong green fluorescence from TPS for probe self-tracking. Upon uptake by cancer cells and entrapment in lysosomes (pH 5.0), the NPs disassemble to yield weak emission of TPS but strong red fluorescence of PheA with restored phototoxicity for PS activation monitoring. Upon light irradiation, the generated reactive oxygen species can cause lysosomal disruption to trigger cell apoptosis. Meanwhile, the probe leaks to the cytoplasm (pH 7.2), where the TPS fluorescence is restored for in situ visualization of the therapeutic response. The probe design thus represents a novel strategy for traceable cancer therapy.

Youyong Yuan;Ryan T.K. Kwok;本忠 唐;Bin Liu

Small

2015-9-1

Fluorescent bioprobes are powerful tools for analytical sensing and optical imaging, which allow direct visualization of biological analytes at the molecular level and offer useful insights into complex biological structures and processes. The sensing and imaging sensitivity of a bioprobe is determined by the brightness and contrast of its fluorescence before and after analyte binding. Emission from a fluorophore is often quenched at high concentration or in aggregate state, which is notoriously known as concentration quenching or aggregation-caused quenching (ACQ). The ACQ effect limits the label-to-analyte ratio and forces researchers to use very dilute solutions of fluorophores. It compels many probes to operate in a fluorescence "turn-off" mode with a narrow scope of practical applications.The unique aggregation-induced emission (AIE) process offers a straightforward solution to the ACQ problem. Typical AIE fluorogens are characterized by their propeller-shaped rotorlike structures, which undergo low-frequency torsional motions as isolated molecules and emit very weakly in solutions. Their aggregates show strong fluorescence mainly due to the restriction of their intramolecular rotations in the aggregate state. This fascinating attribute of AIE fluorogens provides a new platform for the development of fluorescence light-up molecules and photostable nanoaggregates for specific analyte detection and imaging.In this Account, we review our recent AIE work to highlight the utility of AIE effect in the development of new fluorescent bioprobes, which allows the use of highly concentrated fluorogens for biosensing and imaging. The simple design and fluorescence turn-on feature of the molecular AIE bioprobes offer direct visualization of specific analytes and biological processes in aqueous media with higher sensitivity and better accuracy than traditional fluorescence turn-off probes. The AIE dot-based bioprobes with different formulations and surface functionalities show advanced features over quantum dots and small molecule dyes, such as large absorptivity, high luminosity, excellent biocompatibility, free of random blinking, and strong photobleaching resistance. These features enable cancer cell detection, long term cell tracing, and tumor imaging in a noninvasive and high contrast manner. Recent research has significantly expanded the scope of biological applications of AIE fluorogens and offers new strategies to fluorescent bioprobe design. We anticipate that future development on AIE bioprobes will combine one- or multiphoton fluorescence with other modalities (e.g., magnetic resonance imaging) or functionalities (e.g. therapy) to fully demonstrate their potential as a new generation of theranostic reagent. In parallel, the advances in molecular biology will provide more specific bioreceptors, which will enable the development of next generation AIE bioprobes with high selectivity and sensitivity for molecular sensing and imaging.

Dan Ding;Kai Li;Bin Liu;本忠 唐

Accounts of Chemical Research

2013-11-19

We report a new fluorescent light-up probe design strategy by conjugating fluorogens with aggregation-induced emission (AIE) characteristics, e.g. tetraphenylethene with a single-stranded oligonucleotide for homogeneous specific complementary DNA detection in solution.

Yuqiong Li;Ryan T.K. Kwok;本忠 唐;Bin Liu

RSC Advances

2013