Search results for "OXIDATION"
showing 10 items of 1913 documents
Towards Molecular Conductors with a Spin‐Crossover Phenomenon:Crystal Structures, Magnetic Properties and Mössbauer Spectra of[Fe(salten)Mepepy][M(dm…
2005
Three new iron(III) compounds of formula [Fe(salten)Mepepy][M(dmit)2]·CH3CN (M = Ni, Pd, Pt; H2salten = 4-azaheptamethylene-1,7-bis(salicylideneiminate); Mepepy = 1-(pyridin-4-yl)-2-(N-methylpyrrol-2-yl) ethane; dmit2– = 1,3-dithiole-2-thione-4,5-dithiolato) have been synthesised and the crystal structure of each compound has been solved at different temperatures. The structures consist of alternating layers of [M(dmit)2]– units and [Fe(salten)Mepepy] cations. In the Ni compound photo-isomerisation of the Mepepy ligand can be observed in dichloromethane solution. The temperature dependence of the magnetic susceptibility of the compounds reveals a gradual S = 5/2 blabla S = 1/2 spin crossove…
Migration Reactivities of σ-Bonded Ligands of Organoiron and Organocobalt Porphyrins Depending on Different High Oxidation States
1999
Migration reactivities of sigma-bonded organo-iron and -cobalt porphyrins were examined as a function of the compound oxidation state. Migration rates were determined for both the one-electron and two-electron oxidized species produced in the electron-transfer oxidation with different oxidants in acetonitrile at 298 K. The investigated compounds are represented as [(OETPP)Fe(R)](n)()(+), where n = 1 or 2, OETPP = the dianion of 2,3,7,8,12,13,17,18-octaethyl-5,10,15,20-tetraphenylporphyrin, and R = C(6)H(5), 3,5-C(6)F(2)H(3), or C(6)F(5), and as [(TPP)Co(R)](n)()(+), where n = 1 or 2, TPP = the dianion of 5,10,15,20-tetraphenylporphyrin, and R = CH(3) or C(6)H(5). The rapid two-electron oxid…
Synthesis, characterization and a voltammetric study of (Bu4N)2[Mo2Br6]. Oxidation-reduction mechanism of related compounds
1984
The synthesis and characterization of (Bu4N)2[Mo2Br6], obtained from Mo(CO)6, (Bu4N)Br and 1,2-dibromoethane, is described. The electrochemical behaviour of [Mo2Br6]−2 and related species is studied, and an oxidation-reduction mechanism is proposed.
Zinn - Chalkogen - Heterocyclen. V. 2,2,3,3,5,5,6,6-Octamethyl-1.4-dithia-2,3,5,6-tetpastan-ninan, Darstellung und Zersetzung eines Zinnreichen Heter…
1977
Abstract The title compound can be regarded as a sulfur derivative of the corresponding organoditin compound arid contains -formally- tin in the oxidation state 3. It is prepared in analogy to tris (dimethyltinsulfide).
Darstellung und Zerfall von tertiären Hyponitriten
1971
Dicumylhyponitrit (1a), substituierte Dicumylhyponitrite (1b1f) (p-Br, p-Cl, p-CH3, m-CH3, p-CH3O), Bis-[1.1-diphenyl-athyl]-hyponitrit (1h) und Bis-[1.1-dimethyl-pentyl]-hyponitrit (1g) wurden dargestellt. Die tertiaren Hyponitrite zerfallen bereits rasch bei-40 in Stickstoff und freie Alkoxyradikale, die dann zu den entsprechenden Alkoholen und Ketonen weiter reagieren. Die relativen Reaktivitaten von tert.-Butyloxy-und Cumyloxyradikalen hinsichtlich Wasserstoffabstraktion und β-Spaltung wurden fur verschiedene Losungsmittel bestimmt; Cumyloxyradikale neigen starker zur β-Spaltung als tert-Butyloxyradikale. Die freien Alkoxyradikale konnen Polymerisations- und Autoxydationsreaktionen init…
Au deposited on CeO2 prepared by a nanocasting route: A high activity catalyst for CO oxidation
2014
Abstract A set of catalysts comprised of gold on different CeO 2 supports has been prepared by a nanocasting route and characterized by several physicochemical techniques. These catalysts have been tested for CO oxidation and show outstanding catalytic activity. Higher calcination temperatures of the hard template, producing a poorly ordered silica template, have led to a higher amount of oxygen vacancies on the surface of CeO 2 . The presence of surface oxygen defects in the support combined with the deposition of Au nanoparticles ( ca. 3 nm) homogeneously dispersed on the CeO 2 support may explain the excellent behaviour for low temperature CO oxidation. Surprisingly, it has been observed…
Pd/Co3O4 catalyst for CH4 emissions abatement: study of SO2 poisoning effect
2007
A catalyst with 0.7 wt% Pd load supported over Co3O4 oxide was investigated in the methane oxidation by operating under CH4/O2 stoichiometric conditions. The effect of the noble metal addition on the activity of bare Co3O4 was evaluated. Samples were characterized by BET, XRD, TPR and XPS analyses. The SO2 poisoning of Pd catalyst and Co3O4 was studied by performing CH4 oxidation tests under stoichiometric conditions in SO2 (1 ppm or 10 ppm). Experiments evidenced that in our conditions the low amount of SO2 doesn’t influence the Pd behaviour, whereas in presence of 10 ppm of SO2 some deactivation occurs that becomes more evident above 450 °C at which the catalyst doesn’t reach 100% of meth…
Low temperature total oxidation of toluene by bimetallic Au–Ir catalysts
2017
9 Figuras.- 3 Tablas.- Información suplementaria disponible en la página web del editor
2-Tetrahydrofurfuroxo-vanadium-(III) and -(IV) complexes. Synthesis, structures and reactivities of [V2Mg2(μ3,δ2-thffo)2(μ,δ2-thffo)4Cl4]· 2CH2Cl2 an…
1997
Vanadium complexes of 2-tetrahydrofurfuroxide (2-tetrahydrofurylmethoxide) (thffo) with the metal in oxidation state III and IV have been prepared and characterized. The reaction of [VCl3(thf)3] with 1.5 equivalents of [Mg(thffo)2] in tetrahydrofuran (thf) or CH2Cl2 led to the formation of [V2Mg2(µ3,η2-thffo)2(µ,η2-thffo)4Cl4]· 2CH2Cl21. Its structure consists of centrosymmetric tetranuclear molecules and CH2Cl2 of crystallization. Two Mg and two V atoms have distorted octahedral geometry and form a nearly regular Mg2V2 rhombus. The V · · · V distance is 3.266(2) A. The reaction of [VOCl2(thf)2] with Na(thffo) in thf yielded [V2(µ,η2-thffo)2Cl2O2] 2. Two VOCl units are linked by alkoxide ox…
Size and Surface Chemistry Tuning of Silicon Carbide Nanoparticles.
2017
International audience; Chemical transformations on the surface of commercially available 3C-SiC nanoparticles were studied by means of FTIR, XPS, and temperature-programmed desorption mass spectrometry methods. Thermal oxidation of SiC NPs resulted in the formation of a hydroxylated SiO2 surface layer with C3Si–H and CHx groups over the SiO2/SiC interface. Controllable oxidation followed by oxide dissolution in HF or KOH solution allowed the SiC NPs size tuning from 17 to 9 nm. Oxide-free SiC surfaces, terminated by hydroxyls and C3Si–H groups, can be efficiently functionalized by alkenes under thermal or photochemical initiation. Treatment of SiC NPs by HF/HNO3 mixture produces a carbon-e…