Kharash Reaction on Heterogenized Metal Complexes with Bifunctional Ligands
I. G. Tarkhanova,
A. I. Kokorin,
M. G. Gantman,
V. M. Zelikman,
D. S. Tsvetkov
Issue:
Volume 2, Issue 2, April 2013
Pages:
24-32
Abstract: New catalytic systems for polyhalogenmethanes addition to olefins were obtained by immobilization of complexes of Cu, Co, Mn, V (in the vanadyl form) and Fe with bifunctional ligands of aminoalcohols (monoethanolamine), substituted aminoalcohols (N, N-diethylaminoethanol), hydroxyaminoacids (serine, hydroxyproline) on the oxide supports. For Cu, Co, Mn, V the extrem dependence of the catalyst activity on the surface concentration of metal was observed. For iron containing systems the mechanism of the process depends on the concentration of metal — at low concentration (<0.4 wt. %) amine complex are active sites, at high concentration (>1.3 wt. %) — Lewis acid centres. By means of ESR the structure of active sites of the anchored complexes at different metal concentration was stated on the example of copper containing systems. Complexes isolated on the surface of mineral support at the expanse of strong covalent bonding of one of the lignd groups with surface hydroxyls were the most active. Such a structure provides the formation of the surface complexes of divalent copper with four nitrogen atoms in the coordination sphere.
Abstract: New catalytic systems for polyhalogenmethanes addition to olefins were obtained by immobilization of complexes of Cu, Co, Mn, V (in the vanadyl form) and Fe with bifunctional ligands of aminoalcohols (monoethanolamine), substituted aminoalcohols (N, N-diethylaminoethanol), hydroxyaminoacids (serine, hydroxyproline) on the oxide supports. For Cu, Co...
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Initial Stage of Lipid Peroxidation with HO2• Radicals. Kinetic Study
I. P. Ivanova,
I. M. Piskarev,
S. V. Trofimova
Issue:
Volume 2, Issue 2, April 2013
Pages:
44-51
Abstract: Mechanism of initial stage lipid peroxidation with HO2• radicals was investigated. The source of radicals was electric spark discharge radiation on air, rate of radicals generation in sample was 1.2 106 M (l s)1. The kinetic model of process was developed, based on the classical chain oxidation theory. Some process characteristics was calculated by means of numerical solution the system 24 differential equations of chemical kinetics. Initial lipid concentration was taken equals 2 103 M/l. It was shown the unsaturated lipids concentration after 2 hours treatment to spark discharge decrease in ~ 2 times, whereas for saturated lipids decreasing is only 7%. The hydroperoxides production was calculated. The new diene conjugate appearance in treated to spark discharge sample at lipids concentration 2 103 M l1 and treatment time about 10 minutes can't be detected, and just having in sample diens are destroyed. According simulation results, diene conjugates content is increased during treatment to spark discharge radiation at large lipids concentration, having 2 double bonds, (~0.5 M l1). This result is confirmed in experiment with sunflower oil (69% linoleic acid). The dependence of dienes concentration in sample from properties (intensities) external irradiation is ambiguous.
Abstract: Mechanism of initial stage lipid peroxidation with HO2• radicals was investigated. The source of radicals was electric spark discharge radiation on air, rate of radicals generation in sample was 1.2 106 M (l s)1. The kinetic model of process was developed, based on the classical chain oxidation theory. Some process characteristics was calculated ...
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