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91.
Bernd Schetter 《Journal of organometallic chemistry》2004,689(9):1472-1480
N,N′-dicyclohexyl-N-ferrocenoylurea 2, N,N′-diisopropyl-N-ferrocenoylurea 3, N,N′-di-p-tolyl-N-ferrocenoylurea 4 and N,N′-di-tert-butyl-N-ferrocenoylurea 5 were obtained by reaction of ferrocenecarboxylic acid 1 with N,N′-dicyclohexylcarbodiimide (DCC), N,N′-diisopropylcarbodiimide (DIC), N,N′-di-p-tolylcarbodiimide 10 and N,N′-di-tert-butylcarbodiimide 11, respectively. Both N-tert-butyl-N′-ethyl-N-ferrocenoylurea 6 and N′-tert-butyl-N-ethyl-N-ferrocenoylurea 7 were obtained by reaction of 1 with N-tert-butyl-N′-ethylcarbodiimide 12. In all cases a small amount of ferrocenecarboxylic anhydride 8 was formed as a by-product. All compounds were characterized by 1H NMR, 13C NMR, IR and MS. Single crystal X-ray structural analyses were made of 2, 3 and 4. From the consistent results, the reaction products of 1 with carbodiimides appear different from those proposed by some earlier workers. With N-(3-dimethylaminopropyl)-N′-ethylcarbodiimidehydrochloride 9 ferrocenoylurea was not isolated, but the main product was rather 8. The suitability of 8 as acylation reagent was applied by using 9 to obtain N-(3-triethoxysilyl)-propylferrocenecarboxamide in a one-pot reaction from 1 and 3-(triethoxysilyl)-propylamine. 相似文献
92.
A rapid flow-injection method with chemiluminescence (CL) detection is described for the determination of glutathione (GSH).
The method is based on the CL reaction of luminol and hydrogen peroxide. GSH can greatly enhance the chemiluminescence intensity
in 0.1 mol/L borax–sodium hydroxide buffer solution (pH = 9.7). The maximum CL intensity was directly proportional to the
concentration of GSH in the range 3.0 × 10−7–2.0 × 10−5 mol/L, and the detection limit was 6.8 × 10−8 mol/L. The relative standard deviation was 3.4% for 5.0 × 10−6 mol/L of GSH (n = 11).
Received October 23, 2001; accepted June 18, 2002 相似文献
93.
Catalytic oxidation of alcohols to carbonyl compounds with hydrogen peroxide using dinuclear iron complexes 总被引:2,自引:0,他引:2
Oxidation of primary and secondary alcohols has been studied in the presence of [Fe(ind)Cl]2O (1) and [Fe2(OMe)2(PAP)Cl4] (2) (indH = 1,3-bis(2′-pyridylimino)isoindoline; PAP = 1,4-di(2′-pyridyl)aminophthalazine) as catalysts using hydrogen peroxide as primary oxidant. The complexes were found to be suitable catalysts for the oxidation of alcohols to the corresponding carbonyl compounds in acetone as solvent. The reactivity of the alcohols is in the order primary < secondary < cyclic secondary < aromatic. The reaction mechanism in the case of 1 probable involves an iron-based oxidant, while in the case of 2 a free-radical mechanism is suggested. 相似文献
94.
Rong-Li Jia Zhong-Long Ma Cheng-Yang Wang Su-Mei Wang 《Reaction Kinetics and Catalysis Letters》2005,85(1):73-78
Summary Novel amorphous Ni-La-B/-Al2O3 catalysts have been developed for the production of hydrogen peroxide from carbon monoxide, water and oxygen. The experimental investigation confirmed that the catalyst dried at 120ºC in air shows the best initial activity. The deactivation of amorphous Ni-La-B/-Al2O3 catalysts was also studied. 相似文献
95.
脲衍生物对环氧树脂/双氰双胺固化体系潜伏性促进作用研究 总被引:5,自引:1,他引:5
本文用DSC、TBA、旋转粘度计等手段对一系列不同结构及不同取代基取代的脲衍生物对环氧树脂/双氰双胺固化体系的潜伏性促进作用作了考察。结果表明,其促进效果随脲的α位取代烷基碳原子数增加而减弱,而其β、γ位上的取代基团变换时对促进作用无明显影响。由此得出4,4-二(N,N-二甲基)脲二苯甲烷(简称M-二甲)和2,4-二(N,N-二甲基)脲甲苯(简称T-二甲)二种脲衍生物在本丈所考察的28种化合物中具有最显著的促进效果,其中T-二甲的促进活性略高于M-二甲,它们均可使上述固化体系的固化温度降至130℃左右,含有此促进剂的固化体系即使在30℃下贮存,其粘度保持基本不变的时间仍可达三个月以上。 相似文献
96.
97.
N. Suryakiran 《Tetrahedron letters》2007,48(5):877-881
The synthesis of α-halo β-keto-sulfones using potassium halide and hydrogen peroxide as a chemoselective mono halogenation reagent and the synthesis of α,α-symmetrical and asymmetrical dihalo β-keto-sulfones and α-halo, α-alkyl and β-keto-sulfones is described. Base induced cleavage of α-halo β-keto-sulfones, α,α-dihalo β-keto-sulfones, and α-halo, α-alkyl β-keto-sulfones afforded the corresponding halomethyl sulfones, dihalomethyl sulfones and haloalkyl sulfones. 相似文献
98.
Farideh Hosseinpoor 《Tetrahedron letters》2006,47(29):5195-5197
Sulfides were selectively oxidized to the corresponding sulfoxides in good yields with hydrogen peroxide using a manganese(III) Schiff-base complex as a catalyst in glacial acetic acid as solvent under mild conditions. 相似文献
99.
Tatjana Topalovic Vincent A. Nierstrasz Lorenzo Bautista Dragan Jocic Antonio Navarro Marijn M. C. G. Warmoeskerken 《Cellulose (London, England)》2007,14(4):385-400
Hydrogen peroxide can be catalyzed to bleach cotton fibers at temperatures as low as 30°C by incorporating dinuclear tri-μ-oxo
bridged manganese(IV) complex of the ligand 1,4,7-trimethyl-1,4,7-triazacyclononane (MnTACN) as the catalyst in the bleaching
solution. The catalytic system was found to be more selective under the conditions applied than the non-catalytic H2O2 system, showing better bleaching performance while causing slightly lower decrease in degree of polymerization (DP) of cellulose.
In order to gain fundamental knowledge of the bleach effect on cotton fibers and cellulose as its main component, especially
after catalytic bleaching, X-ray Photoelectron Spectroscopy (XPS) was used to study surface chemical effects. The Washburn
method was applied to investigate wetting properties, and liquid porosity was used to obtain pore volume distribution (PVD)
plots. Parallel analyzes performed on model cotton fabric, i.e. “clean” cotton fabric stained with morin - a pigment regularly
found in native cotton fiber, helped to differentiate between pigment oxidation and other bleaching effects produced on the
(regular) industrially scoured cotton fabric. Bleaching was not limited to the chemical action but also affected cotton fiber
capillary parameters most likely due to the removal of non-cellulosic materials as well as chain-shortened cellulose. 相似文献
100.
《Electroanalysis》2006,18(17):1681-1688
Acidic treated multiwalled carbon nanotubes (AMWNTs) were ground with water‐miscible room temperature ionic liquids, 1‐butyl‐3‐methylimidazolium tetrafluoroborate ([bmim]BF4), and resulted in AMWNTs‐[bmim]BF4 composite. Its electrical‐ionic conductivity and optical properties were compared with the other two types of carbon materials‐[bmim]BF4 composites: pyrolytic graphite powder (PGP), pristine multiwalled carbon nanotubes (PMWNTs), through the ac impedance technology and Raman spectroscopy. The impedance data show that AMWNTs‐[bmim]BF4 composite exhibits the highest conductivity. Raman spectra study exhibits that the [bmim]BF4 can form gel with PMWNTs and AMWNTs but only form a viscous liquid with PGP. AMWNTs‐[bmim]BF4 gel modified GC electrode was applied in direct electrochemistry of heme proteins (Hb and HRP) and it catalysis to the reduction of H2O2 was investigated. 相似文献