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991.
Aggregation-induced emission (AIE) is a unique and significant photophysical phenomenon that differs greatly from the commonly acknowledged aggregation-caused emission quenching observed for many π-conjugated planar chromophores. The mechanistic decipherment of the AIE phenomenon is of high importance for the advance of new AIE systems and exploitation of their potential applications. Propeller-like 2,3,4,5-tetraphenylsiloles are archetypal AIE-active luminogens, and have been adopted as a core part in the design of numerous luminescent materials with diverse functionalities. In this review article, we elucidate the impacts of substituents on the AIE activity and shed light on the structure–property relationship of siloles, with the aim of promoting the judicious design of AIE-active functional materials in the future. Recent representative advances of new silole-based functional materials and their potential applications are reviewed as well. 相似文献
992.
Ming Chen Lingzhi Li Han Nie Jiaqi Tong Lulin Yan Bin Xu Jing Zhi Sun Wenjing Tian Zujin Zhao Anjun Qin Ben Zhong Tang 《Chemical science》2015,6(3):1932-1937
Research on aggregation-induced emission (AIE) has been a hot topic. Due to enthusiastic efforts by many researchers, hundreds of AIE luminogens (AIEgens) have been generated which were mainly based on archetypal silole, tetraphenylethene, distyrylanthracene, triphenylethene, and tetraphenyl-1,4-butadiene, etc. To enlarge the family of AIEgens and to enrich their functions, new AIEgens are in high demand. In this work, we report a new kind of AIEgen based on tetraphenylpyrazine (TPP), which could be readily prepared under mild reaction conditions. Furthermore, we show that the TPP derivatives possess a good thermal stability and their emission could be fine-tuned by varying the substituents on their phenyl rings. It is anticipated that TPP derivatives could serve as a new type of widely utilized AIEgen, based on their facile preparation, good thermo-, photo- and chemostabilities, and efficient emission. 相似文献
993.
Synthesis of Bi2WO6/Bi2O3 Composite with Enhanced Photocatalytic Activity by a Facile One‐step Hydrothermal Synthesis Route 下载免费PDF全文
Tianye Wang Fengjun Zhang Guosheng Xiao Shuang Zhong Cong Lu 《Photochemistry and photobiology》2015,91(2):291-297
In this study, the characterization and photocatalytic activity of Bi2WO6/Bi2O3 under visible‐light irradiation was investigated in detail. The results suggested that Bi2WO6/Bi2O3 can be synthesized by a facile one‐pot hydrothermal route using a super big 200 mL Teflon‐lined autoclave with optimal sodium oleate/Bi molar ratio of 1.25. Through the characterization of Bi2WO6/Bi2O3 by X‐ray diffraction, scanning electron microscopy, X‐ray photoelectron spectroscopy, Fourier transform infrared, UV‐vis diffuse reflectance spectra and Photoluminescence spectra, it was found that the as‐prepared composite possessed smaller crystallite size and higher visible‐light responsive than the pure Bi2WO6. Moreover, it was expected that the as‐prepared composites exhibited enhanced photocatalytic activity for the degradation of Rhodamine B under visible‐light irradiation, which could be ascribed to their improved light absorption property and the reduced recombination of the photogenerated electrons and holes during the photocatalytic reaction. In general, this study could provide a principle method to synthesize Bi2WO6/Bi2O3 with enhanced photocatalytic activity by one‐step hydrothermal synthesis route for environmental purification. 相似文献
994.
UVR8 is the only known plant photoreceptor that mediates light responses to UV‐B (280–315 nm) of the solar spectrum. UVR8 perceives a UV‐B signal via light‐induced dimer dissociation, which triggers a wide range of cellular responses involved in photomorphogenesis and photoprotection. Two recent crystal structures of Arabidopsis thaliana UVR8 (AtUVR8) have revealed unusual clustering of UV‐B‐absorbing Trp pigments at the dimer interface and provided a structural framework for further mechanistic investigation. This review summarizes recent advances in spectroscopic, computational and crystallographic studies on UVR8 that are directed toward full understanding of UV‐B perception at the molecular level. 相似文献
995.
Susceptibility of Ureaplasma urealyticum to Methylene Blue‐Mediated Photodynamic Antimicrobial Chemotherapy: An in vitro Study 下载免费PDF全文
Tinglu Ye Bancheng Chen Bo Yu Qili Zhong Guoxin Huang Xiaoping Hu Wei Zhang 《Photochemistry and photobiology》2015,91(4):917-922
The aim of this study was to detect the susceptibility of Ureaplasma urealyticum to methylene blue‐mediated photodynamic antimicrobial chemotherapy (PACT). Three U. urealyticum strains including the standard serotype 1 and 5, and a clinically collected strain were used in this study. Strains were first incubated in 96‐well culture plates in the presence of methylene blue with decreasing concentrations (from 1 to 0.015625 mg mL?1) for 20 or 60 min, and then submitted to irradiation with a light‐emitting diode laser with a power density of 100 mW cm?2 for 8, 17, 34 or 68 min. Regrowth of the strains was performed soon after irradiation. A significant inactivation effect was observed after PACT. Longer incubation time induced more extensive inactivation of U. urealyticum. No difference in response to PACT was observed between the two biovars of U. urealyticum. It was concluded that PACT had a significant inactivation effect on U. urealyticum, and it might be a promising alternative treatment for resistant U. urealyticum infections. 相似文献
996.
The Convenient Synthesis of 11‐Methyl‐3,8‐disubstituted‐12‐aryl‐3,4,7,8,9,12‐hexahydro‐1H‐chromeno[2,3‐b]quinoline‐1,10(2H)‐dione Derivatives 下载免费PDF全文
Guang‐Fan Han Li‐Jun Zhao Li‐Zhuang Chen Jia‐Wei Du Zhong‐Xia Wang 《Journal of heterocyclic chemistry》2015,52(4):1219-1225
The 2‐arylidene‐3‐oxobutanenitrile derivatives 2 were prepared by the Knoevenagel condensation between aldehydes and 3‐oxobutanenitrile 1 , which was obtained by acid hydrolysis of β‐aminocrotononitrile. 3‐Acetyl‐2‐amino‐4H‐chromen‐5(6H)‐one derivatives 3 were synthesized by reaction of 2‐arylidene‐3‐oxobutanenitrile 2 and 5‐substituted‐1,3‐cyclohexanedione in ethylene glycol. The 11‐methyl‐3,8‐disubstituted‐12‐aryl‐3,4,7,8,9,12‐hexahydro‐1H‐chromeno[2,3‐b]quinoline‐1,10(2H)‐dione derivatives 4 were obtained by Friedländer reaction of compounds 3 with 5‐substituted‐1,3‐cyclohexanedione, using p‐toluenesulfonic acid monohydrate as catalyst. The structures of all novel compounds were characterized by elemental analysis, IR, MS, and 1H NMR spectra. The crystal and molecular structure of compound 4f has been determined by single crystal XRD analysis. 相似文献
997.
Zhixiong Zhong Gongke Li Zhibin Luo Zhe Liu Yijuan Shao Wanwen He Jianchao Deng Xingling Luo 《Analytica chimica acta》2015
A carboxylated graphene oxide/polyvinyl chloride (CGO/PVC) material was prepared as a sorbent for the selective extraction of sulphonamides from complex sample. After being dispersed in buffer solution, sample was transferred into the prefabricated solid-phase extraction (SPE) column, which integrated extraction and cleanup into one single-step. A multi-response optimization based on the Box-Behnken design was used to optimize factors affecting extraction efficiency. Compared with the commonly commercial sorbents including MCX, WCX and C18, CGO/PVC hybrid material had higher extraction selectivity and capacity to sulphonamides. The limits of detection and quantification for seven target compounds were in the range of 3.4–7.1 μg/L and 11.4–23.7 μg/L, respectively. The self-assembly SPE cartridge was successfully used to enrich seven analytes in anti-acne cosmetics prior to ion chromatography detection with good recoveries of 87.8–102.0% and relative standard deviations of 1.2–6.4%, implying that this method was suitable for routine analysis of cosmetics. 相似文献
998.
Jun Ren Jinzhou Yang Wei Wang Hailong Guo Zhijun Zuo Jianying Lin Zhong Li 《International journal of quantum chemistry》2015,115(13):853-858
The activity and selectivity of heterogeneous catalysts can be significantly improved by dispersion of another active component in the metal substrate. The impact of Rh promoter on the formation of dimethyl carbonate (DMC) via oxidative carbonylation of methanol on Cu–Rh/AC (activated carbon) catalyst was investigated by density functional theory calculations. The most stable configurations of reacting species (CO, OH, CH3O, monomethyl carbonate, and DMC) adsorbed on the Cu0(zero‐valent copper)/AC and Cu–Rh/AC surfaces were determined on the basis of the calculated results. The reaction energy and activation energy of the rate‐limiting steps on the Cu–Rh/AC and Cu0/AC surfaces were compared. The activation energies of the rate‐limiting step of CO insertion into dimethoxide are 206.3 and 304.8 kJ mol?1 on the Cu–Rh/AC and Cu0/AC surfaces, respectively. The activation energies of the rate‐limiting step of CO insertion into methoxide are 78.5 and 92.7 kJ/mol on the Cu–Rh/AC and Cu0/AC surfaces, respectively. The calculated results indicate that the addition of Rh atom has a significant effect on decreasing the active energy the main pathway for DMC formation. © 2015 Wiley Periodicals, Inc. 相似文献
999.
Paecilomycines A and B,Novel Diterpenoids,Isolated from Insect‐Pathogenic Fungi Paecilomyces sp. ACCC 37762 下载免费PDF全文
Kun Zhou Xiao‐Ling Zhao Li‐Ping Han Meng‐Meng Cao Chuan Chen Bao‐Zhong Shi Du‐Qiang Luo 《Helvetica chimica acta》2015,98(5):642-649
Two new diterpenoids, named paecilomycine A ( 1 ) and paecilomycine B ( 2 ), including a novel skeleton with a five‐membered lactone ring, together with three known labdane diterpenoids, rel‐(1R,3S,4aS,5R,8aS)‐5‐[(3E)‐4‐carboxy‐3‐methylbut‐3‐en‐1‐yl]decahydro‐3‐hydroxy‐1,4a‐dimethyl‐6‐methylidenenaphthalene‐1‐carboxylic acid ( 3 ), botryosphaerin E ( 4 ), and agathic acid ( 5 ), were isolated from solid culture of the insect pathogenic fungi strain Paecilomyces sp. The structures of all compounds were established on the basis of comprehensive spectroscopic studies. The relative configurations of 1 and 2 were determined by single‐crystal X‐ray diffraction analyses. 相似文献
1000.
Clean Synthesis of an Economical 3D Nanochain Network of PdCu Alloy with Enhanced Electrocatalytic Performance towards Ethanol Oxidation 下载免费PDF全文
Jiawei Liu Zhao Huang Kai Cai Huan Zhang Dr. Zhicheng Lu Tingting Li Yunpeng Zuo Prof. Heyou Han 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(49):17779-17785
A one‐pot method for the fast synthesis of a 3D nanochain network (NNC) of PdCu alloy without any surfactants is described. The composition of the as‐prepared PdCu alloy catalysts can be precisely controlled by changing the precursor ratio of Pd to Cu. First, the Cu content changes the electronic structure of Pd in the 3D NNC of PdCu alloy. Second, the 3D network structure offers large open pores, high surface areas, and self‐supported properties. Third, the surfactant‐free strategy results in a relatively clean surface. These factors all contribute to better electrocatalytic activity and durability towards ethanol oxidation. Moreover, the use of copper in the alloy lowers the price of the catalyst by replacing the noble metal palladium with non‐noble metal copper. The composition‐optimized Pd80Cu20 alloy in the 3D NNC catalyst shows an increased electrochemically active surface area (80.95 m2 g?1) and a 3.62‐fold enhancement of mass activity (6.16 A mg?1) over a commercial Pd/C catalyst. 相似文献