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1.
采用原位显微红外光谱电化学方法研究了聚电解质中不同阳离子(Li+,Na+,K+和TBA+)存在下铁氰化钾的电化学还原过程.观察到支持电解质阳离子对Fe(CN)3-/4-6振动频率的影响,探讨了还原反应机理 相似文献
2.
采用模式空间变换技术使多组份光谱重叠体系中各组份得到有效地分离从而达到部分或所有组份定性及定量的目的。方法分辨效果好,定性定量结果可靠。无论光谱重叠程度如何,只要光谱间存在一定的差异即可得到较好的结果。将该方法用于人工合成食用色素多组份体系中各组份的同时测定,获得了较好的结果。 相似文献
3.
采用模式空间变换技术使多组份光谱重叠体系中各组份得到有效地分离从而达到部分或所有组份定性及定量的目的.方法分辨效果好,定性定量结果可靠.无论光谱重叠程度如何,只要光谱间存在一定的差异即可得到较好的结果.将该方法用于人工合成食用色素多组份体系中各组份的同时测定,获得了较好的结果. 相似文献
4.
一种新型固体电解质的导电性的研究 总被引:3,自引:0,他引:3
对多种新型Li离子导电的polymer-in-salt固体电解质的导电性及其影响因素进行了研究。这种固体电解质是将很少量的单离子聚合物电解质-聚丙烯酸锂熔于低温共熔锂盐中得到的,室温电导率为10^-5S/cm(29℃),较由聚氧化乙烯(PEO)制造的polymer-in-salt固体电解质,电导率有明显地提高。 相似文献
5.
一种新型聚合物电解质的研制 总被引:2,自引:0,他引:2
合成了聚 (甲基丙烯酸甲酯 丙烯腈 甲基丙烯酸锂 ) (简记为PMAML)新型聚合物电解质基质材料 ,把它与聚偏氟乙烯 (PVDF)共混制备了凝胶化的聚合物电解质 .通过核磁共振波谱确定了PMAML的组份含量 ,并用扫描电镜观察了该聚合物基质膜的表面形貌 .利用交流阻抗技术测试了其电导率 ,室温下电导率可达2 5× 10 - 3S·cm- 1 .采用线性伏安扫描方法研究了该聚合物电解质的电化学稳定性 ,其电化学稳定窗口为4 5V .通过受限扩散实验测得电解质中离子的扩散系数为 8 12× 10 - 7cm2 ·s- 1 .组装的聚合物电解质锂离子电池首次充放电效率为 89% ,前 5次循环容量基本稳定 . 相似文献
6.
用现场显微红外光谱电化学技术研究了聚电解质中TCNQ在电化学还原过程中二价阴离子在Li^+离子之间形成的离子对。离子对效应随阳离子浓度增加而增大。观察到一个文献中未曾报道的谱带位于2130cm^-1附近。 相似文献
7.
PVA-CMC-KOH-H2O碱性聚合物电解质研究 总被引:8,自引:0,他引:8
由聚乙烯醇(PVA)与羧甲基纤维素钠(CMC)制备PVA-CMC-KOH-H2O碱性聚合物电解质膜,应用交流阻抗、循环伏安、差热分析和红外光谱等实验方法表征、研究其性能.结果表明,该碱性聚合物电解质的室温电导率可达到10-2S.cm-1数量级,在不锈钢惰性电极上的电化学稳定窗口约为1.6 V.另外,还研究了聚合物电解质膜中KOH、H2O和CMC对体系电导率的影响以及PVA-CMC-KOH-H2O碱性聚合物电解质在N i/MH电池中的初步应用.初步结果表明,由PVA-CMC-KOH-H2O聚合物电解质组装的N i/MH电池,其低倍率放电性能较好. 相似文献
8.
采用等温溶解平衡法测定了四元交互体系Li~+,K~+/Cl~-,75℃的溶解度和平衡溶液的物化性质(密度、粘度、折光率).该四元交互体系50,75℃的溶解度等温图有5个相区:即Li_2SO_4·H_2O,KLiSO_4,KCl,K_2SO_4,LiCl·H_2O,7条单变量曲线,3个共饱点,其中Li_2O_4·H)2O+KCl+LiCl·H_2O为一致零变量点。用我们以往提出的经验公式处理了平衡溶液的密度和折光率,由所测得的溶解度数据,求得了高温和高锂浓度下的电解质溶液Pitzer模型的离子相互作用参数。计算了各平衡溶液中盐的活度和水的活度。还计算了该四元交互体系25℃的溶解度,考察了Pitzer电解质溶液理论在水-盐溶解度计算中的应用。 相似文献
9.
10.
以共聚型氯醇橡胶(ECO)为基体, 通过在基体中溶解不同浓度的LiCF3SO3制备了一系列聚合物电解质. 利用差示扫描量热技术(DSC)研究了该体系锂盐浓度对聚合物电解质玻璃化转变温度的影响, 用傅里叶变换红外光谱(FTIR)研究了体系内锂盐与聚合物基体的相互作用. 结果表明, 在相同锂盐浓度下, ECO基聚合物电解质的室温离子电导率比传统的聚环氧乙烷(PEO)基聚合物电解质提高了2个数量级, 并且体系电导率在升降温循环测试中没有弛豫现象产生. 这是由于ECO基体的非结晶性所致. 相似文献
11.
用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%. 相似文献
12.
Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields. 相似文献
13.
Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction
Laurent Gavara Thomas Boisse Jean-Pierre Hénichart Adam Daïch Philippe Gautret 《Tetrahedron》2010,66(38):7544-5571
In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments. 相似文献
14.
The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula. 相似文献
15.
Rebecca J. Burton Mandy L. CrowtherNeal J. Fazakerley Shaun M. FilleryBarry M. Hayter Jason G. KettleCaroline A. McMillan Paula PerkinsPeter Robins Peter M. SmithEmma J. Williams Gail L. Wrigley 《Tetrahedron letters》2013
The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines. 相似文献
16.
KMnO4-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields. 相似文献
17.
N. A. Nedolya 《Chemistry of Heterocyclic Compounds》2008,44(10):1165-1219
The review contains a concise historical account and information on the most significant researches undertaken by the staff
at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry
of Heterocyclic Compounds.
Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee.
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008. 相似文献
18.
A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL. 相似文献
19.
Regiospecific and direct imidation of the methyl C(sp3)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products. 相似文献
20.
A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions. 相似文献