نتایج جستجو برای: epoxidation
تعداد نتایج: 1907 فیلتر نتایج به سال:
The oxidation of copper catalysts during ethylene epoxidation was characterized using in situ photoemission spectroscopy and electron microscopy. Gas chromatography, proton-transfer reaction mass spectrometry and electron-ionization mass spectrometry were used to characterize the catalytic properties of the oxidized copper. We find that copper corrodes during epoxidation in a 1 : 1 mixture of o...
The mono-epoxidation of geraniol by dimethyldioxirane was carried out in various solvents. In all cases, the product ratios for the 2,3 and 6,7 mono-epoxides were in agreement with literature values. Kinetic studies were carried out at 23 degrees C in the following dried solvent systems: acetone (k(2) = 1.49 M(-1)s(-1)), carbon tetrachloride/acetone(9/1, k(2)=2.19 M(-1)s(-1)), and methanol/acet...
The asymmetric synthesis of vicinal diols is a very important process in organic chemistry, as it allows the preparation of a large variety of useful derivatives. One of the most interesting methods to accomplish this synthesis is the asymmetric epoxidation of activated olefins, catalysed by chiral organic or organometallic catalysts. In this paper we study, with computational tools, two possib...
A novel interfacial hybrid epoxidation catalyst was designed with a new immobilization method for homogeneous catalysts by coating an inorganic support with an organic polymer film containing active sites. The titanium silsesquioxane (TiPOSS) complex, which contains a single-site titanium active center, was immobilized successfully by in-situ copolymerization on a mesoporous SBA-15-supported po...
A series of Vand/or Ti-loading MCM-41 catalysts are successfully synthesized with a hydrothermal method. The photocatalytic and thermal epoxidations of cyclohexene in the presence of tert-butyl hydroperoxide (t-BuOOH) were investigated with real-time monitored by NIR-Raman spectroscopy. It suggests that both Vand Ti-loading can be responsible for the cyclohexene epoxidation. Moreover, the compl...
vo2+ and its complexes with ethylenediamine (en), acetylacetonate (acac), 2, 2’-bipyridine(bpy) ligands, immobilized within nanoreactors of al-mcm-41 designated as vo2+/al-mcm-41 or vol2/al-mcm-41, were prepared and characterized by x-ray powder diffraction (xrd), ft-ir, bet nitrogen adsorption-desorption and chemical analysis techniques. vo2+/al-mcm-41 and vol2/al-mcm-41 were found to catalyze...
Terpene epoxides are considered as potential primary intermediates in the synthesis of numerous green polymers including epoxy resins, polycarbonates, nonisocyanate polyurethanes and even some polyamides. In this chapter we describe recent efforts from our group to develop catalytic noncatalytic processes for terpene epoxidation using a variety oxidizing agents process intensification methods. ...
A two-dimensional nanolayered polyoxomolybdate, [4,4´-H2bipy] [Mo7O22].H2O (1), where 4,4´-bipy = 4,4´-bipyridine, was prepared and characterized by FT-IR and atomic absorption spectroscopies, transmission electron microscopy (TEM), X-ray single crystal and powder diffraction (XRD), and thermogravimetric analysis. The catalytic performance of 1 was assessed in the epoxidation of some olefins em...
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