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11.
Roxana S. Timofte 《Tetrahedron letters》2004,45(1):39-42
High surface area silica pellets are excellent supports for the preparation of silica supported reagents and solid-phase basal linkers through reaction with (RO)3Si(CH2)3FG (FG=NH2, NHMe, Cl, NHC(O)NH2, OC(O)CMe(CH2), NCO, NEt2). High loadings (0.66-2.15 mmol g−1) of grafted silane materials are realised at synthetically useful loadings per pellet (ca. 0.06 mmol). Preliminary trials show that trial linker chemistry and ligand synthesis can be carried out on these materials and that these reactions can be monitored by solid state 13C NMR studies on individual pellets. 相似文献
12.
SbPO4, a phosphate with a layered structure, was tested as an electrode material for lithium cells spanning the 3.0-0.0 V range. Two main electrochemical processes were detected as extensive plateaus at ca. 1.6 and 0.7 V in galvanostatic measurements. The first process was found to be irreversible, thus excluding a potential intercalation-like mechanism for the reaction and being better interpreted as a decomposition reaction leading to the formation of elemental Sb. This precludes the use of this compound as a cathodic material for lithium cells. By contrast, the process at 0.7 V is reversible and can be ascribed to the formation of lithium-antimony alloys. The best electrochemical response was obtained by cycling the cell at a C/20 discharge rate over the voltage range 1.25-0.25 V. Under these conditions, the cell delivers an average capacity of 165 Ah/kg—a value greater than those reported for other phosphates—upon successive cycling. 相似文献
13.
Xu Zhang Dongfeng Xue Meinan Liu Henryk Ratajczak Dongli Xu 《Journal of Molecular Structure》2005,754(1-3):25-30
On the basis of the crystallographic characteristics of lithium niobate (LN) crystals, Law of Bravais and Pauling's third rule (i.e. Polyhedral Sharing Rule) are employed with the aim to find the relationship between the crystal structure and morphological faces of LN powders. In order to validate our analytical results, we have successfully synthesized LN powders and measured the corresponding X-ray powder diffraction. Our results show that the structural analysis is consistent with the experimental data and is helpful and effective for us to control the single-crystal growth and to design superstructures at the specific plane, starting from the viewpoint of the microscopic behaviors of constituent chemical bonds and polyhedra in the crystallographic frame. 相似文献
14.
With urea 1,5-diaryl-3-hydroxy-4-methylsulfonyl-3-pyrrolin-2-ones form the 3-amino derivatives of pyrrolones. In reactions
with hydrazine hydrate and ethylenediamine the corresponding salts are formed. With ethylenediamine at 180–185°C the double
salt of 3-hydroxy-4-methylsulfonyl-1,5-diphenyl-3-pyrrolin-2-one forms N,N′-di(4-methylsulfonyl-1,5-diphenyl-3-pyrrolin-2-on-3-yl)-ethylenediamine.
The reaction with o-phenylenediamine gives 2,3-diaryl-4-methylsulfonylpyrrolo-[2,3-b]quinoxalines.
__________
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, 1631–1636, November, 2007. 相似文献
15.
本文讨论了29个不对称色酸双偶氮膦酸型显色剂的分子联接性指数,并将其与结构选择性因子相结合,用于偶氮类剂结构与铈显色反应灵敏度的相关性研究,讨论了显色剂结构对显色反应灵敏度的影响。 相似文献
16.
介绍催化光度法测定锰的分析方法,讨论各显色体系中的灵敏度、测定范围和干扰情况,比较了测定锰的显色剂。引用文献58篇。 相似文献
17.
J. P. Doumerc J. M. Cocciantelli J. C. Grenier M. Pouchard P. Hagenmuller 《无机化学与普通化学杂志》1993,619(4):748-752
Magnetic susceptibility of V2O5 and of the α-, ?-, δ- and γ-LixV2O5 bronzes prepared either at high or at room temperature has been measured between liquid helium and ambient temperature. The results are representative of the localized character of the V4+ ion d-electron and, for high enough x-values, of the existence of antiferromagnetic interactions in a low dimensional system. The intrachain exchange integral J has been determined using the Bonner/Fischer model for Heisenberg chains with S = 1/2 spin. It is larger for the γ- than for the δ-phase. This result as well as the occurrence of long range ordering below TN ≈ 130 K in the γ-phase may be ascribed to ordering of V4+ and V5+ ions in the former bronze and to the random distribution of V4+ ions in the latter one. 相似文献
18.
本非水电池体系由Li负极、多孔石墨电极和电解质溶液组成;电解质溶液由无机溶剂POCl_3(或有机溶剂硝基苯)和溶解在该溶剂中的活性物质(KIBr_2)及支持电解质构成。该电池体系的开路电压为8.50伏左右,放电性能良好,可望在实际中得到应用。此外,对电池体系的反应机理也作了初步的探讨。 相似文献
19.
HUANG Xiao-wen SHI Peng-fei 《高等学校化学研究》2006,22(1):73-75
IntroductionLithium ion batteries are key components of mobiletelephones and portable computers.Among the knownLi-intercalation materials for lithium ion battery cath-odes,LiCoO2,LiNiO2,and LiMn2O4have been stud-ied extensively[1—3].LiCoO2is nowused in c… 相似文献
20.
Mohammad R.?SaidiEmail author Mohammad?Nazari 《Monatshefte für Chemie / Chemical Monthly》2004,135(3):309-312
Summary. The solid LiClO4-mediated one-pot reaction of aldehydes with secondary amines and C nucleophiles afforded the corresponding aminoalkylation products in high yields. Unlike the previous reported procedure, the aminoalkylation of aldehyde was achieved in the presence of only 0.5 equivalents of solid lithium perchlorate in dichloromethane as the solvent with good to high yields at room temperature. 相似文献