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41.
0IntroductionRecently,thecompoundscontaining1H-1,2,4-tr-iazolegrouphaveattractedmuchinterestbecauseoftheirexhibitingsomefungicidalactivityandplantgrowthregulatingactivity犤1犦,andshowingantibacterialactivityagainstPucciniareconditeandrootsgrowthregulationforcucumber犤2犦.Also,suchcompoundsareincreasinglybeingstudiedbecauseofthecoordinationchemistryofazolesactingasligandsintransitionmetalcompounds.Asamatteroffact,thetriazolederivativeshavebeenextensivelyusedasterminalandbridgingligands,andthey… 相似文献
42.
Zheng-Huan Lin Hong-Yan Dou Jin Li Cheng-Xue Zhao 《Research on Chemical Intermediates》2005,31(9):867-873
The H-abstractions/spin-trapping reactions with primary, secondary and tertiary alcohols of new 'magic blue' reagents, namely,
the blue F113 (CClF2CCl2F) solution containing bis{perfluoro[1-(2-fluorosulfonyl)ethoxy]ethyl} nitroxide (2) and perfluoro[1-nitroso-1-(2-fluorosulfonyl)ethoxy]ethane (3) both generated in the reaction of perfluoro[2-(2-fluorosulfonyl)ethoxy]propionyl peroxide (1) with sodium nitrite in F113 at room temperature, were studied by EPR. Based on the interpretation of the EPR spectra of
the spin adducts, nitroxides, the region-selectivity of H-abstraction has been disclosed and the possible mechanistic paths
of H-abstraction have also been discussed. EPR of H-abstraction by using 'magic blue' reagents can also be used for producing
various hydroxyalkyl radicals from common alcohols. 相似文献
43.
1 INTRODUCTION Benzimidazole is an interesting heterocyclic compound because it is found in various naturally occurring drugs, such as omeprazole, astemizole and emedastine difumarate[1]. The efficacy of sub- stituted benzimidazoles in the treatment of parasitic infections is well known[2~4]. Substituted benzimid- azole moieties are established pharmacophores in parasitic chemotherapy. Bis(2-benzimidazole) and some substituted bis(benzimidazol-2-yl)alkanes have attracted much interest … 相似文献
44.
Ke Tao Hongjing Dou Kang Sun 《Colloids and surfaces. A, Physicochemical and engineering aspects》2006,290(1-3):70-76
Dextran-Fe3O4 hybrid clusters were fabricated by coprecipitating ferric and ferrous ions in the presence of dextran, and after characterization of these clusters combined with calculation based on classical nucleation theory, a structure model of these hybrid clusters was proposed. The hybrid cluster was believed including small Fe3O4 nanoparticles and dextran which acted as both nucleating agent and stabilizer, so that exist in both the inside of magnetite nanoparticles and the periphery of the hybrid clusters. Besides, the effects of WCD (weightiron cation:weightdextran) and molecular weight of dextran on the size, morphology and magnetic property of clusters were also investigated in this paper. It was found that the variation of WCD and molecular weight of dextran have great effect on the size of the hybrid clusters, but have almost no effect on the size of the Fe3O4 nanoparticles. The characterization of magnetic property demonstrated that the Fe3O4 nanoparticles are of a single domain and the saturation magnetization was affected by the size of dextran-Fe3O4 hybrid clusters. 相似文献
45.
Yandong Dou Kenry Dr. Jiang Liu Jianze Jiang Prof. Qing Zhu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(28):6896-6901
o-Alkenylation of unprotected phenols has been developed by direct C−H functionalization catalyzed by PdII. This work features phenol group as a directing group and realizes highly site-selective C−H bond functionalization of phenols to achieve the corresponding products in moderate to excellent yields at 60 °C. The advantages of this reaction include unprecedented C−H functionalization using phenol as a directing group, high regioselectivity, good substrate scope, mild reaction conditions, and high efficiency. To the best of our knowledge, this is the first example of a regioselective C−H alkenylation of unprotected phenols utilizing phenolic hydroxyl group as a directing group. The alkenylation of unprotected tyrosine and intramolecular cyclization are also successfully carried out under this catalytic system in good yields. Furthermore, this novel method enables a late-stage modification of complex phenol-containing bioactive molecules toward a diversity-oriented drug discovery. 相似文献
46.
Chao Dou Xili Jing Shuguang Li Junjun Wu Qingbo Wang 《Optical and Quantum Electronics》2018,50(6):255
The characteristics of a novel dual-core photonic crystal fiber are investigated. In the center of photonic crystal fiber, an energy transmission channel is introduced. The optimized photonic crystal fiber can be used for polarization splitter, which has a short length and low loss. 相似文献
47.
Yang Min Dr. Chuandong Dou Prof. Hongkun Tian Prof. Jun Liu Prof. Lixiang Wang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(13):4364-4372
The B←N unit has a large dipole and it is isoelectronic to C−C moiety with no dipole. Incorporating B←N units into π-conjugated system is a powerful strategy to design organic small molecules and polymers with intriguing opto-electronic properties and excellent opto-electronic device performance. However, it is unclear how the B←N unit affects electronic structures and opto-electronic properties of large π-conjugated molecules. In this work, to address this question, we developed three dibenzo-azaacene molecules in which two B←N units were introduced at different positions. Although the dibenzo-azaacene skeleton is fully π-conjugated, the effect of B←N unit on the electronic structures of the adjacent rings is much stronger than that of the distant rings. As a result, the three molecules with isomerized B←N incorporation patterns possess different electronic structures and exhibit tunable opto-electronic properties. Among the three molecules, the centrosymmetrical molecule exhibits higher LUMO/HOMO energy levels than those of the two axisymmetrical molecules. When used as the active layer in organic field-effect transistors (OFETs), while the two axisymmetrical molecules show unipolar electron transporting property, the centrosymmetrical molecule exhibits ambipolar hole and electron transporting behavior. This work not only deepens our understanding on organoboron π-conjugated molecules, but also indicates a new strategy to tune opto-electronic properties of organic semiconductors for excellent device performance. 相似文献
48.
Fei Dou Cephas Small Francoise Provencher Jason Ferreira Xuhua Wang Elham Rezasoltani Hongmei Liu Xinping Zhang 《Journal of Polymer Science.Polymer Physics》2017,55(12):940-947
We investigate the influence of particle plasmons on exciton and charge generation and recombination processes in the blend of poly (9‐(1‐octylnonyl)‐9H‐carbazole‐benzothiadiazole‐4,7‐diyl‐2,5‐thiophenediyl) (PCDTBT) and [6,6]‐phenyl‐C70butyric acid methyl ester (PC70BM). The particle plasmons are generated from gold nanoparticles, which are embedded into PCDTBT:PC70BM blend. For the blend with gold nanoparticles, we observe enhance light harvesting. Despite the enhanced light collection, we find that the quasi‐steady‐state charge generation has not been influenced by the particle plasmons. However, the generation and recombination of long‐lived (sub‐millisecond) polaron paris have been significantly enhanced: from untrapped state in the pristine blend to the trapped state in the gold nanoparticle‐embedded blend. This result implies that the plasmon‐influenced polarons are trapped at the broadband geminate polaron pair (GPP) state. This state acts as an intermediate state, which either leads to the formation of charge transfer excitons (CTXs) or free charge carriers. In our case, the particle plasmon‐influenced polarons are trapped in the GPP state, which leads to the formation of CTXs. For this reason, we do not observe the enhanced charge generation in PCDTBT:PC70BM blend with particle plasmon resonance. Finally, we revealed that the long‐lived polarons mainly resulted from the localization by particle plasmons. The macroscopic modification in the blend film made negligible contributions to this influence. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017 , 55, 940–947 相似文献
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