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31.
Structural and Theoretical Insights into the AIE Attributes of Phosphindole Oxide: The Balance Between Rigidity and Flexibility
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Fan Bu Dr. Erjing Wang Dr. Qian Peng Dr. Rongrong Hu Prof. Anjun Qin Prof. Zujin Zhao Prof. Ben Zhong Tang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(11):4440-4449
Multiple intramolecular motions consume the excited‐state energy of luminogenic molecules upon photoexcitation and lower the emission efficiency. The low frequency rotational motion of aromatic rings can be facilely restricted by steric constraint in the condensed phase, but the high frequency bond stretching motion can hardly be suppressed by aggregation. In this work, three phosphorus‐containing heterocycles, 1,2,3,4,5‐pentaphenylphosphole‐1‐oxide (PPPO), 1,2,3‐triphenylphosphindole‐1‐oxide (TPPIO), and 1,2,3‐triphenylphosphindole (TPPI), were synthesized and characterized. Their optical properties, crystal‐packing manners, electronic features, and fluorescence dynamics were systematically investigated, and theoretical calculations were performed to decipher structure–property relationships. The results reveal that these luminogens are weak emitters in solutions but show strong emission in aggregates, exhibiting obvious aggregation‐induced emission (AIE) features. The aggregation‐insensitive stretching motion, which is dominant in PPPO, is lowered in TPPIO, enabling TPPIO to fluoresce much more efficiently than PPPO in aggregates. The stretching motion is even more lowered in TPPI, but its relatively planar conformation suffers emission quenching due to strong π–π stacking interactions in aggregates. Therefore, a twisted molecular conformation consisting of a rigid stator and a rotatable periphery is demonstrated to be a rational design for more efficient AIE luminogens. 相似文献
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Zujin Zhao Tao Jiang Yanju Guo Liyuan Ding Bairong He Zhengfeng Chang Jacky W. Y. Lam Jianzhao Liu Carrie Y. K. Chan Ping Lu Liwen Xu Huayu Qiu Ben Zhong Tang 《Journal of polymer science. Part A, Polymer chemistry》2012,50(11):2265-2274
Hydrosilylation polymerizations of 1,1‐dimethyl‐2,5‐bis(4‐ethynylphenyl)‐3,4‐diphenylsilole with aromatic silylhydrides including 1,4‐bis(dimethylsilyl)benzene, 4,4′‐bis(dimethylsilyl)biphenyl, 2,5‐bis(dimethylsilyl)thiophene, and 2,7‐bis(dimethylsilyl)‐9,9‐dihexylfluorene in the presence of Rh(PPh3)3Cl catalyst in refluxed tetrahydrofuran afford a series of silole‐containing poly(silylenevinylene)s. Under optimum condition, the alkyne polyhydrosilylation reactions progress efficiently and regioselectively, yielding polymers with high molecular weights (Mw up to 95,300) and good stereoregularity (E content close to 99%) in high yields (up to 92%). The polymers are processable and thermally stable, with high decomposition temperatures in the range of 420?449 °C corresponding to 5% weight loss. They are weakly fluorescent in the solution state but become emissive in the aggregate and film states, demonstrating their aggregation‐enhanced emission characteristics. The explosive sensing capabilities of the polymers are examined in both solution and aggregate states. The emissions of the polymers aggregates in aqueous mixture are quenched more efficiently by picric acid in an exponential pattern with high quenching constants (up to 27,949 L mol?1), suggesting that the polymers aggregates are sensitive chemosensors for explosive detection. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 相似文献
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Yi Xiong Jiajie Zeng Bin Chen Jacky W. Y. Lam Zujin Zhao Shuming Chen Ben Zhong Tang 《中国化学快报》2019,30(3):592-596
New aggregation-induced emission molecules of carbazole-substituted siloles are prepared, based on which efficient non-doped OLEDs are fabricated, offering high external quantum efficiencies of up to 5.63%. 相似文献
36.
Zeyan Zhuang Jun Dai Maoxing Yu Jianqing Li Pingchuan Shen Rong Hu Xiaoding Lou Zujin Zhao Ben Zhong Tang 《Chemical science》2020,11(13):3405
Photodynamic therapy (PDT) is considered a pioneering and effective modality for cancer treatment, but it is still facing challenges of hypoxic tumors. Recently, Type I PDT, as an effective strategy to address this issue, has drawn considerable attention. Few reports are available on the capability for Type I reactive oxygen species (ROS) generation of purely organic photosensitizers (PSs). Herein, we report two new Type I PSs, α-TPA-PIO and β-TPA-PIO, from phosphindole oxide-based isomers with efficient Type I ROS generation abilities. A detailed study on photophysical and photochemical mechanisms is conducted to shed light on the molecular design of PSs based on the Type I mechanism. The in vitro results demonstrate that these two PSs can selectively accumulate in a neutral lipid region, particularly in the endoplasmic reticulum (ER), of cells and efficiently induce ER-stress mediated apoptosis and autophagy in PDT. In vivo models indicate that β-TPA-PIO successfully achieves remarkable tumor ablation. The ROS-based ER stress triggered by β-TPA-PIO-mediated PDT has high potential as a precursor of the immunostimulatory effect for immunotherapy. This work presents a comprehensive protocol for Type I-based purely organic PSs and highlights the significance of considering the working mechanism in the design of PSs for the optimization of cancer treatment protocols.Phosphindole oxide-based photosensitizers with Type I reactive oxygen species generation ability are developed and used for endoplasmic reticulum stress-mediated photodynamic therapy of tumors. 相似文献
37.
Bingjia Xu Zicun Song Minmin Zhang Qingqing Zhang Long Jiang Cao Xu Lijun Zhong Changlin Su Qiqi Ban Cong Liu Fengqiang Sun Yi Zhang Zhenguo Chi Zujin Zhao Guang Shi 《Chemical science》2021,12(47):15556
A pair of axially chiral organic enantiomers were facilely prepared through a one-pot sequential synthesis. They exhibit circularly polarized luminescence activities and have thermally activated delayed fluorescence (TADF) and aggregation-induced emission enhancement properties. Meanwhile, these two enantiomers present remarkable and reversible thermochromism in the crystalline state, enabling dual-colour TADF switching between orange and red. However, when they form cocrystals, the resulting racemate shows opposite thermochromic behaviors. These intriguing results probably emanate from their different optical activities, leading to distinct molecular packing modes and molecular conformation variations. Moreover, information encryption based on thermochromism of organic enantiomers and their racemate has been presented for the first time. This work may expand the application scope of chiral organic luminogens and pave a new way to construct intelligent luminescent systems.A pair of axially chiral organic enantiomers with circularly polarized thermally activated delayed fluorescence and aggregation-induced emission enhancement properties show opposite thermochromic behaviors to their racemate. 相似文献
38.
XUE Zengquan LIU Weimin HOU Shimin SHI Zujin GU Zhennan LIU Hongwen ZHAO Xingyu ZHANG Zhaoxiang WU Mianlei PENG Lianmao WU Quande 《中国科学A辑(英文版)》2000,43(11):1182-1188
Single-wall carbon nanotubes (SWCNTs) were synthesized and purified. A water colloid of SWCNTs was prepared and used to assemble
SWCNTs onto a gold film surface. Scanning tunneling microscopy (STM) images showed that short SWCNTs stood on gold film surfaces.
Using STM tips made of SWCNTs, a crystal grain image of a gold thin film and an atomic resolution image of highly oriented
pyrolytic graphite were successfully obtained. The electrical properties of short SWCNTs, which stood on the surface of gold
film, were measured using STM. That SWCNTs stand on gold thin films is a promising technique for studying structures and properties
of carbon nanotubes, as well as assembling and fabricating high-intensity coherent electron sources, field emission flat panel
display, tips for scanning probe microscopes, new nanoelectronic devices, etc. 相似文献
39.
Applications of Mathematics - As observed by Yamazaki, the third component b3 of the magnetic field can be estimated by the corresponding component u3 of the velocity field in Lλ (2 ?... 相似文献