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31.
Stephen Brand John Milton Martin F. Jones Christopher M. Rayner 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1):367-368
A new method for the synthesis of cyclic and acyclic optically active S,O-acetals is reported, along with subsequent stereocontrolled transformations, culminating in a synthesis of the important antiviral nucleoside Lamivudine. 相似文献
32.
Lin-Yan Xu Chun-Yu Liu Shi-Yuan Liu Zhi-Gang Ren David James Young Jian-Ping Lang 《Tetrahedron》2017,73(22):3125-3132
One palladium dichloride adduct of a phosphine-pyridine ligand N-diphenylphosphanyl-2-aminopyridine (L1) [(L1)PdCl2] (1) has been prepared and structurally characterized. Compound 1 can be used as an effective catalyst for the Suzuki-Miyaura cross-coupling reactions of unreactive aryl chlorides with aryl boronic acids, and worked much better than its mono- or bidentate phosphine ligands. The reactions with a wide scope of substrates proceeded to give desired products in good to excellent yields. 相似文献
33.
微量稀土对工业纯铝中杂质相的变质行为 总被引:15,自引:5,他引:15
采用SE,EDAX,TEM他稀土对工业纯铝中富Fe(Si)杂质相的变质作用及机制,结果表明:富铈混合稀土(RE)是一种有效变质剂,可使铝中杂质相由粗大长针(条)状或骨骼变细小的团球状或短棒状,且分布均均匀,提高了材料的力学性能(尤其是塑性),其变质机制主要是因稀土在固/液界面前前沿的富集,导致了稀土进入杂质相形成(AlFeSiRE)的复杂化合物,或吸附在杂质相表面阻碍其长大,但过量稀土易导致第二相数量增多,降低材料塑性,其加入量应小于 0.07%(质量分数)。 相似文献
34.
35.
《Journal of Polymer Science.Polymer Physics》2018,56(16):1135-1143
Block copolymers with donor and acceptor conjugated polymer blocks provide an approach to dictating the donor–accepter interfacial structure and understanding its relationship to charge separation and photovoltaic performance. We report the preparation of a series of donor‐linker‐acceptor block copolymers with poly(3‐hexylthiophene) (P3HT) donor blocks, poly((9,9‐dioctylfluorene)‐2,7‐diyl‐alt‐[4,7‐bis(thiophen‐5‐yl)‐2,1,3‐benzothiadiazole]‐2′,2″‐diyl) (PFTBT) acceptor blocks, and varying lengths of oligo‐ethylene glycol (OEG) chains as the linkers. Morphological analysis shows that the linkers increase polymer crystallinity while a combination of optical and photovoltaic measurements shows that the insertion of a flexible spacer reduces fluorescence quenching and photovoltaic efficiencies of solution processed photovoltaic devices. Density functional theory (DFT) simulations indicate that the linking groups reduce both charge separation and recombination rates, and block copolymers with flexible linkers will likely rotate to assume a nonplanar orientation, resulting in a significant loss of overlap at the donor–linker–acceptor interface. This work provides a systematic study of the role of linker length on the photovoltaic performance of donor–linker–acceptor block copolymers and indicates that linkers should be designed to control both the electronic properties and relative orientations of conjugated polymers at the interface. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018 , 56, 1135–1143 相似文献
36.
Efficient and modular syntheses of chiral 2-(2-hydroxyaryl)alcohols (HAROLs), novel 1,4-diols carrying one phenolic and one alcohol hydroxyl group, have been developed which led to generation of a small library of structurally diverse HAROLs in enantiomerically pure form. Of the different HAROLs examined, a HAROL based on the indan backbone exhibited the highest activity and enantioselectivity in the 1,2-addition of certain organometallic compounds to aldehydes in the presence of Ti(OiPr)4 (up to 97% y, 88% ee) and performed as a hydrogen-bond donor organocatalyst in the Morita-Baylis-Hillman reaction, promoted by trialkylphosphines. 相似文献
37.
建立了一种用稀盐酸溶解样品,标准工作溶液中匹配钾,ICP-AES测定高铼酸钾中19种杂质元素的方法。在选定的仪器工作条件下,样品加标回收率(%)分别为:钠94.4~101、钙98.8~102、铝98.1~102、镁95.8~99.1、钴98.4~101、钼97.3~103、钛97.6~102、钒96.6~106、锆96.2~97.7、铬97.8~101、铜98.1~108、铁92.9~104、锰95.5~98.4、镍93.6~101、钯93.3~101、铅96.5~103、锌95.2~103、铂95.9~99.9、铑94.5~96.3;方法精密度RSD%(n=7)分别为:钠2.0~5.5、镁1.1~3.5、铝0.9~2.5、钙1.5~7.3、钴1.1~3.1、钼0.9~4.5、钛1.0~2.8、钒1.6~4.0、锆1.4~3.6、铬0.77~4.6、铜0.74~1.8、铁1.3~3.8、锰1.1~2.0、镍0.99~5.0、钯1.1~2.4、铅1.3~9.1、锌0.80~6.7、铂1.2~10、铑0.78~8.6。方法简便、快速、准确, 满足生产分析要求。 相似文献
38.
39.
低共熔溶剂(DESs)因具有合成容易、价格低廉、环境友好、挥发性低、溶解能力强、可生物降解、结构可设计等特点,被认为是一种绿色溶剂。近年来,研究者通过深入研究低共熔溶剂的性质,结合低共熔溶剂的特点,将其替代传统的有机溶剂,在混合物分离过程中开展了大量的研究工作,包括:酸性气体(如CO2、CO2和H2S)吸收、生物活性物质萃取、燃料油品中含硫和含氮化合物的脱除、油酚混合物分离、芳烃和脂肪烃混合物的分离、醇水混合物分离、生物柴油合成过程中甘油的脱除等。本文分析了低共熔溶剂的结构、性质和特点,综述了低共熔溶剂在分离领域的最新研究成果,探讨了低共熔溶剂在混合物分离应用中存在的问题,展望了低共熔溶剂的发展趋势。 相似文献
40.
Kalyanmoy Jana Somnath Das Tithi Maity Maidul Hossain Subhas Chandra Debnath 《Journal of Coordination Chemistry》2018,71(10):1497-1509
A new Co(II) complex of general formula [Co(L)2] has been synthesized from a NNO tridentate Schiff base ligand, 2-[(piperidin-2-ylmethylimino)-methyl]-phenol (L). The title complex is characterized by elemental, spectroscopic, antibacterial, and single crystal X-ray structural studies. X-Ray crystallography reveals that the complex shows a distorted octahedral geometry around the Co(II) ion. The complex was tested against several bacteria and shows good antibacterial activities against almost all of the bacteria. The interactions of the title complex with calf thymus deoxyribonucleic acid (CT-DNA) have been investigated by electronic absorption and fluorescence spectroscopy, showing that the complex interacts with CT-DNA via partial intercalation. Thermogravimetric analysis (TGA) of the complex has also been reported and the result shows that the complex is thermally stable up to 134 °C. 相似文献