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31.
ZHANG Jing HUANG Ru-dan ZHU Oin-lei HU Chang-wen 《高等学校化学研究》2007,23(4):483-485
Introduction In recent years,considerable attention has been paid to supramolecular networks based on metal organic building blocks because of their potential applications in diverse fields,such as,catalysis,optics,sensors, magnetism,and molecular recognition[1-3].On the ba- 相似文献
32.
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34.
Summary. A highly efficient, selective, fast, and cheap protocol is developed for oxidation of aromatic amines and alcohols utilizing
34% hydrogen peroxide in water catalyzed by some W- and Mo-based heteropolyoxometalates. Findings showed that dodecatungstophosphoric
acid, H3PW12O40, was the most efficient catalyst in the examined oxidation reactions. This methodology may prove to be a valuable alternative
for eco-friendly green oxidation. Inherent simplicity, easy work up, and using regenerable catalysts were other key aspects
of this oxidation protocol. 相似文献
35.
A novel diselenide was synthesized in good yield via only four steps from phenol, and was employed as the catalyst for the Baeyer-Villiger oxidation with 30% H2O2 to obtain lactones in good yields. 相似文献
36.
选择性氧化含氰基的对硝基苯硫醚 总被引:2,自引:0,他引:2
选择性氧化含氰基的对硝基苯硫醚岳国仁,王建华,张正(南京大学化学系南京210008)关键词含氰基硫醚,选择性氧化,四水合过硼酸钠据报道[1]对硝基苯磺酰基乙腈的合成,反应时间长,可采用四水合过硼酸钠(NaBO3·4H2O)作为氧化剂,受到重视[2,3... 相似文献
37.
报道了用Co3O4 作覆盖氧化剂分析有机锗化合物中碳氢元素的方法。通过对 9个样品的十几次分析 ,碳、氢的相对误差分别小于± 1.30 % ,4 .4 0 %。方法简便 ,结果稳定可靠 ,可用于含锗有机化合物的碳氢分析。 相似文献
38.
Bogumil Brzezinski Zbigniew Rozwadowski Teresa Dziembowska Georg Zundel 《Journal of Molecular Structure》1998,440(1-3):73-79
Three di-Schiff bases of 2-hydroxy-5-methyl-isophthalaldehyde with 4-R-anilines (R=H, CH3, OCH3) and their 1:1 complexes with HClO4 were studied by FT-IR, 1H, and 13C NMR spectroscopy in acetonitrile and [2H3]acetonitrile solutions, respectively. In di-Schiff bases intramolecular OH…N hydrogen bonds have been detected; however, they show no proton polarizability. Hydrogen-bonded systems with fast proton fluctuation and large proton polarizability have been found in the 1:1 complexes of di-Schiff bases with HClO4. 相似文献
39.
An enzymatic assay for glucose based on the use of the fluorescent probe for hydrogen peroxide, europium(III) tetracycline (EuTc), is described. The weakly fluorescent EuTc and enzymatically generated H2O2 form a strongly fluorescent complex (EuTc–H2O2) whose fluorescence decay profile is significantly different. Since the decay time of EuTc–H2O2 is in the microseconds time domain, fluorescence can be detected in the time-resolved mode, thus enabling substantial reduction of background fluorescence. The scheme represents the first H2O2-based time-resolved fluorescence assay for glucose not requiring the presence of a peroxidase. The time-resolved assay (with a delay time of 60 s and using endpoint detection) enables glucose to be determined at levels as low as 2.2 mol L–1, with a dynamic range of 2.2–100 mol L–1. The method also was adapted to a kinetic assay in order to cover higher glucose levels (mmol L–1 range). The latter was validated by analyzing spiked serum samples and gave a good linear relationship for glucose levels from 2.5 to 55.5 mmol L–1. Noteworthy features of the assay include easy accessibility of the probe, large Stokes shift, a line-like fluorescence peaking at 616 nm, stability towards oxygen, a working pH of approximately 7, and its suitability for both kinetic and endpoint determination. 相似文献
40.
J. Baran A. J. Barnes M. K. Marchewka A. Pietraszko H. Ratajczak 《Journal of Molecular Structure》1997,416(1-3):33-42
The crystal structure of bis(betaine)-selenic acid has been determined by X-ray diffraction as orthorhombic, space group Pbca, with a = 11.591(2), b = 22.930(5), c = 12.045(2) Å and Z = 8. The crystal comprises hydrogen selenate ions, HSeO−4, and two distinct betaine molecules, which are held together into a complex by short hydrogen bonds. One of the betaine molecules is present as the zwitterion form (CH3)3N+---CH2---COO− and the second occurs as the protonated form (CH3)3N+---CH2---COOH. Powder FTIR and Raman spectra were measured. An assignment of the observed bands to vibrations of the hydrogen bonds and internal vibrations of the hydrogen selenate ion and the betaine molecules is proposed. 相似文献