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61.
Piezoelectric diffuse reflectance spectroelectrochemistry (PDRSEC), a new technique of diffuse reflectance spectroelectrochemistry (DRSEC) in combination with electrochemical quartz crystal microbalance (EQCM), was developed to study the electrochemical copolymerization of aniline and o-anthranilic acid in 1.0 mol l(-1) HClO4 and the properties of these copolymers. The DRSEC using an integral sphere was proven to possess a higher optical sensitivity at the unpolished piezoelectric quartz crystal electrodes used than the mirror reflectance spectroelectrochemistry mode. The copolymers grown from the copolymerization bath of different molar fractions of o-anthranilic acid (F1, relative to the total amount of the two monomers) showed intermediate properties between those of the homopolymers, which varied gradually with F1. The swelling/dissolution behavior of the copolymers vs solution pH was traced via the EQCM frequency and resistance signals, and its large dependence on F1 was found and discussed. In a HAc-NaAc buffer solution at pH 5.6, the amount of adsorbed lysozyme was found to be positively correlated with F1, via an EQCM impedance investigation, demonstrating the feasibility of using poly(aniline-co-o-anthranilic acid) as a load-adjustable immobilization matrix for cationic proteins. The novel PDRSEC method proposed is highly recommended for surface electrochemistry studies at relatively rough electrodes. 相似文献
62.
The hydrosilylation reaction of octa(hydrido)silsesquioxane with ω‐halo‐1‐alkenes and other unsaturated substrates allows attachment of 8 long‐chain functionalized alkyls on the cubic Si8O12 skeleton. Pt/C and H2PtCl6 have been adopted as the catalysts, the yields being 74–98% for compounds 2–9 . For terminal alkenes, the hydrosilylation follows the anti‐Markonikov's rule. The morphological state of 2–9 ranges from viscous liquid to crystalline materials. The pyrolysis results indicate that 7 , a material of hard spherical core and soft flexible shell, may likely act as nanometer‐size ball bearings up to more than 400 °C. The X‐ray structure of 9 reveals that the molecule is required to possess a center of symmetry crystallographically. The linear arms on 9 , except for two of them, are virtually all‐trans in conformation, not counting the ω‐C‐Cl bond. 相似文献
63.
A New Asterosaponin from the Starfish Culcita novaeguineae 总被引:1,自引:0,他引:1
HaiFengTANG YangHuaYI LingLI PengSUN DaZhengZHOU BaoShuLIU 《中国化学快报》2005,16(5):619-622
A new asterosaponin named novaeguinoside A, along with a known saponin, asteronyl pentaglycoside sulfate, was isolated from the starfish Culcita novaeguineae. The new compound was identitied to be sodium 6α-O-{β-D-fucopyranosyl-(1→2)-β-D-fucopyranosyl-(1→4)-[β-D-quinovopyranosyl-(1→2)]-β-D-xylopyranosyl-(1→3)-[β-D-quinovopyranosyl}-5α-pregn-9(11)-en-20-one-3β-yl-sulfate by extensive spectral analysis and chemical evidence. 相似文献
64.
65.
设计合成了2-(N'-乙基咔唑-3'-烯基)-8-羟基喹啉. 以UV-Vis, 1H NMR, FT-IR, 元素分析和MS进行了结构表征, 并测定了产物的光致发光(PL)性质. 运用Gaussian98量子化学程序包, 采用B3LYP密度泛函(DFT)的方法, 在6-31G(d,p)水平上对分子的几何构型进行结构优化; 预测目标产物的振动光谱, 结果表明与实验值相符. 相似文献
66.
The compound has tetragonal symmetry, space group I4 m2 with: a=b=6.315(2) and c = 15.000(2) Å and contains 6 formula units. Diffraction data with 0 < 2θ < 50° (MoKα radiation) were collected on a Nonius CAD-4 automatic diffractometer within the octant hkl. The structure was solved by Patterson synthesis and refined by full-matrix least squares to a final R(F) of 4.9% for 159 independent reflections with I > 3σ(I). The structure consists of a stacking of gallium triangular-faced dodecahedra linked to each others through direct and bifurcated Ga? Ga bonds in a non-compact netting leaving room for a sublattice of rubidium atoms with shortened Rb? Rb distances. 相似文献
67.
Zhou Q Liu X Zhao Y Jia N Liu L Yan M Jiang Z 《Chemical communications (Cambridge, England)》2005,(39):4941-4942
Single crystal tin nano-rod arrays were fabricated by the electrodeposition method when amphiphilic triblock copolymer P123 was used as a soft template at a concentration much lower than that for forming a liquid crystalline phase. 相似文献
68.
Zhang WW Li HF Liu L Xie JL Lu CS Zhou Y Ren XM Meng QJ 《Journal of colloid and interface science》2003,261(1):82-87
A series of thiol-functionalied azobenzene derivatives (RAzoCnSH: R=H for n=3-6, abbreviated as AzoCnSH; R=CH(3)CONH for n=4, abbreviated as aaAzoC4SH) on gold electrodes were prepared and their self-assembly and electrochemical properties were studied by cyclic voltammetry. They all formed uniform and reproducible self-assembled monolayers (SAMs) on gold and showed well-behaved voltammetric responses in aqueous solution. Both the length of the alkyl chain spacer and the H-bonding of the end acetamino group had effects on the stability and the electrochemical kinetics of the SAMs, and the effect of the H-bonding was dominant. The surface coverage of the SAMs (AzoCnSH) is gradually increased with an increase of the alkyl chain spacer length, whereas the presence of the terminal acetamino group leads to a greater increase of the surface coverage. At a low scan rate, voltammetric responses corresponding to an irreversible two-electron, two-proton reduction/oxidation of the trans-azobenzene redox center were obtained in the range of +300 mV and -800 mV, which exhibited very large peak-to-peak splitting. At a high scan rate of 500 mV/s, two steps of reversible one-electron, one-proton reduction/oxidation corresponding to the cis-isomer in azobenzene-thiol SAMs (n is odd) was clearly observed between +300 and -200 mV. The apparent electron-transfer rate is decreased with increasing distance between the azobenzene redox center and the gold electrode. The existence of the end acetamino group which restricted the conformational change during the redox process also led to a decrease of the standard rate constant, and this restriction effect is more predominant than the distance effect. 相似文献
69.
含二氧杂环异黄酮的合成 总被引:8,自引:0,他引:8
本文报道含有3', 4'-亚甲二氧基, 3', 4'-亚乙二氧基, 3, 4'-三亚甲二氧基的异黄酮类化合物的合成, 所得25个新化合物的结构经元素分析、^1H NMR谱确证; 紫外光谱表明有异黄酮特征吸收。文中并对反应机理进行了探讨。 相似文献
70.
碱性介质中高择优取向(220)镍电极上丙醇的电氧化 总被引:5,自引:0,他引:5
对1.0mol/LNiSO4和0.5mol/L H3BO3体系,控制电位为一1.25V,沉积60min,制得高择优取向镍电极。该镍电极经X射线衍射测定其织构度TC220为92%。采用循环伏安法研究了1mol/L NaOH溶液中高择翁取向镍电极上丙醇的电催化氧化机理有活性,结果表明:高择优取向镍电极对正丙醇的电催化活性高,对异丙醇的电催化活性小;推导出正丙醇的电氧化动力学方程,运用稳态极经曲线测定了 相似文献