共查询到19条相似文献,搜索用时 125 毫秒
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以2-氯噻吩、多聚甲醛为原料,以离子液体[C2mim]Br、[C3mim]Br、[C4mim]Br、[C5mim]Br、[C6mim]Br、[C7mim]Br、[C8mim]Br、[C12mim]Br、[Bmim]PF6、[Bmim]BF4、[Bmim]C4F9SO3和[Bmim]Cl为催化剂进行氯甲基化反应,得到产物2-氯-3-氯甲基噻吩。研究表明,离子液体可以促进2-氯噻吩的氯甲基化反应,具有相转移催化剂的效果,并且以[C4mim]Br和[C8mim]Br的催化效果为佳。反应最佳条件为:离子液体[C8mim]Br摩尔分数为5%(相对于2-氯噻吩),温度40℃,反应时间8h,产物产率可达92.1%。 相似文献
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以LiH2PO4、LiF和V2O5为原料,蔗糖为还原剂,用碳热还原法合成了Li3V2[(PO4)1-xFx]3/C(x=0、0.02、0.05、0.08、0.10和0.15),并用X射线衍射、Fourier变换红外光谱、循环伏安、交流阻抗谱和恒流充放电技术研究了F-掺杂对材料结构和电化学性能的影响.结果表明:F-掺杂Li3V2(PO4)3/C与纯Li3V2(PO4)3/C均为单斜结构,但少量的F-掺杂可提高电极反应可逆程度和电导率,降低电荷传递阻抗;在所得的F-掺杂材料中,Li3V2[(PO4)0.95F0.05]3/C具有较好的电化学性能.在3.0~4.2V (vs.Li/Li+)循环时,电极的0.5C放电容量为124.4 mA·h/g,50次循环后容量保持率为98.5%,15C下的放电容量为84.7mA·h/g,50次循环后容量保持率为97.4%,而Li3V2(PO4)3/C的仅为59.2 mA·h/g和89.0%. 相似文献
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采用一步合成法制备了以甘氨酸为阳离子、磷钨酸为阴离子的功能化杂多酸盐[Gly]_3PW_(12)O_(40)。以[Gly]_3PW_(12)O_(40)为催化剂,以离子液体[Hmim]PF6、[Hmim]BF4、[Bmim]PF6、[Bmim]BF4分别为萃取剂,以过氧化氢为氧化剂,构建了杂多酸盐耦合离子液体的催化氧化脱硫体系。研究表明,以[Hmim]PF6为萃取剂可以获得最佳的脱硫效果。采用单因素实验研究了脱硫工艺条件对[Gly]_3PW_(12)O_(40)/[Hmim]PF6/H2O2体系脱硫效果的影响。结果表明,在n(过氧化氢)/n(硫)=4、反应时间为90 min、反应温度为60℃、n[Gly]_3PW_(12)O_(40)/n(硫)=0.025、[Hmim]PF6用量为1 m L条件下,燃料油的脱硫率可达99.2%,并且脱硫体系[Gly]_3PW_(12)O_(40)/[Hmim]PF6具有很好的重复使用性能。 相似文献
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《高校化学工程学报》2017,(3)
采用典型的湿化学法制备了2%(wt)FeF_3包覆的Li[Li_(0.2)Mn_(0.54)Ni_(0.13)Co_(0.13)]O_2材料,并且通过XRD,SEM及TEM等技术来分析材料的微观结构和形貌。结果显示,在Li[Li_(0.2)Mn_(0.54)Ni_(0.13)Co_(0.13)]O_2材料表面包覆着一层5~20 nm厚的FeF_3薄膜。通过电化学性能测试发现,2%(wt)FeF_3@Li[Li_(0.2)Mn_(0.54)Ni_(0.13)Co_(0.13)]O_2样品的首次库伦效率更高,高倍率性能更佳,循环性能更加稳定。在0.5C倍率下循环100次后,其容量保持率仍有94.2%,放电比容量为190.6 m Ah×g~(-1)。同时电化学阻抗结果表明,FeF_3包覆层能够抑制Li[Li_(0.2)Mn_(0.54)Ni_(0.13)Co_(0.13)]O_2和电解液之间的副反应,稳定材料的层状结构。 相似文献
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《应用化工》2017,(1):10-13
研究了甲基磷酸二甲酯(DMMP)含量对1 mol/L Li PF6/EC∶DEC∶EMC(1∶1∶1)电解液的电化学稳定性、热稳定性及电导率的影响,并首次将含DMMP的阻燃电解液应用于高压材料LiNi_(0.5)Mn_(1.5)O_4中。结果表明,加入DMMP添加剂后电解液的热稳定性得到提高,但是该添加剂电解液的电导率有所降低。研究了DMMP对LiNi_(0.5)Mn_(1.5)O_4扣式电池的电化学性能的影响,循环伏安测试表明,几乎不影响电解液在高压条件下的使用,充放电测试结果表明,DMMP的使用会降低电池的循环性能,当DMMP含量为5%时,对电池的循环性能影响较小。此外,交流阻抗(EIS)分析表明,DMMP对循环性能影响的主要原因是内阻随着循环的增加而增大。 相似文献
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《应用化工》2022,(1):10-14
研究了甲基磷酸二甲酯(DMMP)含量对1 mol/L Li PF6/EC∶DEC∶EMC(1∶1∶1)电解液的电化学稳定性、热稳定性及电导率的影响,并首次将含DMMP的阻燃电解液应用于高压材料LiNi_(0.5)Mn_(1.5)O_4中。结果表明,加入DMMP添加剂后电解液的热稳定性得到提高,但是该添加剂电解液的电导率有所降低。研究了DMMP对LiNi_(0.5)Mn_(1.5)O_4扣式电池的电化学性能的影响,循环伏安测试表明,几乎不影响电解液在高压条件下的使用,充放电测试结果表明,DMMP的使用会降低电池的循环性能,当DMMP含量为5%时,对电池的循环性能影响较小。此外,交流阻抗(EIS)分析表明,DMMP对循环性能影响的主要原因是内阻随着循环的增加而增大。 相似文献
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The in vitro antifungal activity of compounds 1-3 ({[(CH3)2NCH2]2C6H3}R2SnX; (where X=Cl, R=n-Bu for 1, X=Br, R=n-Bu for 2 and x=PF6, R=n=Bu for 3)) was estimated with the help of a modified microdilution format of the M27-A guidelines and was compared with in vitro activity of their diphenyltin(IV) analogues 4 and 5 (where X=Br, R=Ph for 4 and X=PF6, R=Ph for 5), and of drugs currently in clinical use (ketoconazole, fluconazole and amphotericin B). It was found that in coordinating solvents the more soluble derivative 2 is less active than the phenyl one (4), and compounds 1 and 3 are even inactive.In this paper, the in vitro antitumour activity of ionic diphenyltin(IV) complexes 4 and 5 against seven tumoural cell lines of human origin is also reported. The preparation and characterization (H1, C13 and Sn119 NMR spectroscopy and electrospray ionization mass spectrometry) of the novel compound 3 is mentioned too. 相似文献
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In the multi-functionalized ionic liquid compositions (MFILC), composed of 1-n-butyl-2-diphenylphosphino-3-methylimidazolium
hexafluorophosphate, [BDPPMIM]PF6), 1-(2-piperid-1-yl-ethyl)-3-methylimidazolium hexafluorophosphate, [PEMIM]PF6), and 1-n-butyl-3-methylimidazolium
hexafluorophosphate ([BMIM]PF6), PdCl2 served as an efficient catalyst for Heck reactions of aryl iodides and bromides. The
built-up PdCl2-MFILC, including stoichiometrically consumed base of [PEMIM]PF6, could be reused at least for seven cycles
without activity loss.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
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Two soluble conjugated polyfluorenes, poly{9,9‐dioctylfluorene‐2,7‐diyl‐co‐4,4′‐bis[2‐(4‐phenyl)‐2‐cyanovinyl]triphenylamine}(PF‐BCT) and poly{9,9‐dioctylfluorene‐2,7‐diyl‐co‐3,6‐bis[2‐(4‐phenyl)‐2‐cyanovinyl]‐9‐octyl carbazole}(PF‐BCC), have been synthesized from 2,7‐dibromo‐9,9‐dioctylfluorene and 4,4′‐bis[2‐(4‐bromophenyl)‐ 2‐cyanovinyl]triphenylamine or 3,6‐bis[2‐(4‐bromophenyl)‐2‐cyanovinyl]‐9‐octyl carbazole comonomers through a Suzuki polymerization reaction. The copolymers are characterized by gel permeation chromatography, elemental analysis, thermogravimetric analysis. The polymers have good thermal stability with 5 wt % loss temperatures of more than 380°C. Cyclic voltammetry measurements show that the polymers present good electron and hole‐injection abilities. PF‐BCC possesses higher oxidization potential than that of PF‐BCT, which indicates that PF‐BCT has better hole injection ability. The photophysical properties of the polymers are investigated in both solutions and spinning‐coated films. Compared to that of PF‐BCC, the absorption and emission peaks of PF‐BCT bathochromic shift in the solid film or solution states. Single layer light‐emitting devices have been fabricated in the ITO/PEDOT: PSS/polymer/Ca/Al configuration. The electroluminescence (EL) device based on PF‐BCT shows yellow emission with the current efficiency of 0.21 cd/A, while PF‐BCC shows greenish yellow emission with the current efficiency of 0.08 cd/A. In addition, to improve the electroluminescence of PF‐BCC, a PVK layer is introduced, the brightness and efficiency get improved to 700 cd/m2 and 0.12 cd/A, respectively. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献
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Poplar wood pulp was adopted as both frame and precursor for the synthesis of pulp fiber (PF)/reduced graphene oxide composite via a simple and low-cost method. In this method, the PF based on graphene (PFG) composite film electrode was prepared by a simple vacuum filtration process with various ratios (PF: reduced graphene oxide (RGO)?=?5:1, PF:RGO?=?5:2, PF:RGO?=?5:3, PF:RGO?=?5:4, PF:RGO?=?5:5). In terms of special structures, the PFG can be used as electrodes without metal-collector, adhesives, and additives. The optimal ratio (PF:RGO?=?5:4) film electrode displayed a high areal-specific capacitance of 683 mF/cm2 at 1?mA/cm2 with a mass of 5.3?mg/cm2 (specific capacitance of 129?F/g) and good cycling stability (87.5% capacitance retention after 10,000 cycles at 5?mA/cm2) as well as excellent rate capability and high flexibility (suitable for any angle, even 180°). Moreover, the device could possess a maximum energy density of 47.71?μWh/cm2 and a maximum power density of 1251?μW/cm2. These results suggest that the composite PGF film is a promising electrode material. 相似文献
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聚乙二醇单全氟壬烯基醚的合成与表面性能 总被引:1,自引:0,他引:1
以硼酸、聚乙二醇(PEG)和全氟壬烯为主要原料制备了聚乙二醇单全氟壬烯基醚,以红外光谱表征,并研究了其水溶液的表面性能。硼酸与聚乙二醇酯化反应以四氢呋喃作溶剂,n(PEG)∶n(硼酸)=3∶1,80℃反应3h,生成硼酸三聚乙二醇酯。聚乙二醇另一未反应的羟基再与全氟壬烯进行醚化反应,N,N-二甲基苯胺作缚酸剂,n(C9F18)∶n(硼酸三聚乙二醇酯)=3∶1,80℃反应1h,得硼酸聚乙二醇单全氟壬烯醚三酯,然后在70℃水解反应8h,得聚乙二醇单全氟壬烯基醚,收率90%左右(以全氟壬烯计)。测定了聚乙二醇单全氟壬烯基醚[C9F17O(CH2CH2O)nH]的表面张力和临界胶束浓度(CMC)。C9F17O(CH2CH2O)nH能大大降低水的表面张力,n越小,其表面张力越低。C9F17O(CH2CH2O)8H的CMC、γCMC和浊点分别为1.26×10-4mol/L,24.4mN/m,54.3℃。 相似文献
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制备了三种不同阳离子侧链长度的离子液体[C_nMIM]PF_6(其中n=4、6、8),以它们为萃取剂,以双硫腙为螯合剂,构建了离子液体[C_nMIM]PF_6-双硫腙萃取体系。研究了该萃取体系对含铅废水中Pb~(2+)的萃取性能。研究发现,阳离子侧链增加有利于提高Pb~(2+)的萃取效果。另外,考察了萃取时间、萃取温度、pH值、含铅废水与离子液体的体积比对Pb~(2+)萃取率的影响。结果表明:[C_8MIM]PF_6-双硫腙萃取体系对含铅废水中Pb~(2+)的萃取率可达93.5%,并且Pb~(2+)萃取率受pH值影响很大。 相似文献
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11C‐ and 18F‐Labeled Radioligands for P‐Glycoprotein Imaging by Positron Emission Tomography 下载免费PDF全文
Dr. Mariangela Cantore Marcel Benadiba Philip H. Elsinga Chantal Kwizera Rudi A. J. O. Dierckx Nicola Antonio Colabufo Gert Luurtsema 《ChemMedChem》2016,11(1):108-118
P‐Glycoprotein (P‐gp) is an efflux transporter widely expressed at the human blood–brain barrier. It is involved in xenobiotics efflux and in onset and progression of neurodegenerative disorders. For these reasons, there is great interest in the assessment of P‐gp expression and function by noninvasive techniques such as positron emission tomography (PET). Three radiolabeled aryloxazole derivatives: 2‐[2‐(2‐methyl‐(11C)‐5‐methoxyphenyl)oxazol‐4‐ylmethyl]‐6,7‐dimethoxy‐1,2,3,4‐tetrahydroisoquinoline ([11C]‐ 5 ); 2‐[2‐(2‐fluoromethyl‐(18F)‐5‐methoxyphenyl)oxazol‐4‐ylmethyl]‐6,7‐dimethoxy‐1,2,3,4‐tetra‐hydroisoquinoline ([18F]‐ 6 ); and 2‐[2‐(2‐fluoroethyl‐(18F)‐5‐methoxyphenyl)oxazol‐4‐ylmethyl]‐6,7‐dimethoxy‐1,2,3,4‐tetrahydroisoquinoline ([18F]‐ 7 ), were tested in several in vitro biological assays to assess the effect of the aryl substituent in terms of potency and mechanism of action toward P‐gp. Methyl derivative [11C]‐ 5 is a potent P‐gp substrate, whereas the corresponding fluoroethyl derivative [18F]‐ 7 is a P‐gp inhibitor. Fluoromethyl compound [18F]‐ 6 is classified as a non‐transported P‐gp substrate, because its efflux increases after cyclosporine A modulation. These studies revealed a promising substrate and inhibitor, [11C]‐ 5 and [18F]‐ 7 , respectively, for in vivo imaging of P‐gp by using PET. 相似文献