Search results for "Monoxide"
showing 10 items of 133 documents
{Bis[2-(diisopropylphosphanyl)ethyl]amine}carbonyl(tetrahydroborato)cobalt(I)
2018
In the structure of title borohydride pincer complex, [Co(BH4)(C16H37NP2)(CO)], the cobalt(I) metal exhibits a distorted square-pyramidal coordination geometry with the basal positions occupied by the P and N atoms of the tridentate ligand and by the C atom of the carbon monoxide ligand. In the crystal, molecules interact only by van der Waals forces.
Elementary steps in heterogeneous catalysis: The basis for environmental chemistry
2017
Kataliza stała się obecnie alternatywnym sposobem na natychmiastowe tworzenie produktu chemicznego z uwagi na niższą barierę energetyczną (między cząsteczkami a katalizatorami). Kataliza heterogenna obejmuje przyspieszenie reakcji chemicznej poprzez oddziaływanie cząsteczek związanych z powierzchnią ciała stałego. Jest to dyscyplina, która obejmuje różne aspekty chemii: chemię nieorganiczną i analityczną w celu scharakteryzowania katalizatorów i form tych katalizatorów. Chemia przemysłowa następnie łączy te wszystkie zagadnienia razem, aby zrozumieć chemiczną manipulację ciał stałych, reakcję chemiczną i inżynierię energetyczną oraz przenoszenie ciepła i masy w tych procesach katalitycznych…
Palladium-Catalyzed Hydroxycarbonylation of Aryl and Vinyl Bromides by Mixed Acetic Formic Anhydride
2006
The palladium-catalyzed hydroxycarbonylation of aryl and vinyl bromides in the presence of acetic anhydride and lithium formate as a carbon monoxide source has been developed. The combination of palladium(II) acetate with 1,1'-bis(diphenylphosphino)ferrocene (dppf) is an efficient catalytic system when the reaction is carried out at 120 °C.
High affinity of "arbor" iron porphyrins for dioxygen
1998
International audience; The equilibrium rates of dioxygen and carbon monoxide binding have been measured for a series of capped iron porphyrins called "arbor". The affinity for dioxygen of these models is 100-fold higher than the highest previously reported values.
First Synthesis of β-Keto Sulfoxides by a Palladium-Catalyzed Carbonylative Suzuki Reaction
2005
[reaction: see text] An unprecedented palladium-catalyzed three-component cross-coupling reaction between alpha-bromo sulfoxide, carbon monoxide, and aromatic boronic acids provides a new and efficient approach to the synthesis of beta-ketosulfoxides. The reaction takes place under mild conditions with a wide range of variously substituted aryl and heteroaryl boronic acids. The carbonylative cross-coupling reaction is strongly favored over competing direct cross-coupling and homocoupling processes, except with boronic acids carrying strong electron-withdrawing substituents.
Pumice-Supported Nickel Catalysts
1997
A series of nickel catalysts supported on pumice was prepared by precipitation and impregnation techniques. The influence of the calcination and reduction temperatures on the structural properties such as lattice parameters and particle dimensions of the oxide precursors and of the reduced catalysts was investigated by X-ray diffraction measurements. The effect of structural changes on the catalytic activity in the hydrogenation of carbon monoxide has been evaluated. The turnover frequencies, as well as product distributions, are discussed in terms of the influence of the support properties and of its interaction with the metal. Changes of the C2+yield over CH4yield ratio versus nickel disp…
Surface Study of Pumice Supported Nickel Catalysts Used in the Hydrogenation of CO
1998
A series of pumice supported nickel catalysts used in the CO hydrogenation reaction were characterised by X-ray photoelectron spectroscopy. Qualitative and quantitative analysis of the XPS peaks have shown the effect of the calcination conditions on the chemical state of the nickel before hydrogenation and the particle size of the metal after reduction. Calcination at high temperature determined enrichment of sodium ions on the surface of the support and also on the metal particles. After exposure to the gas mixture CO/H2, formation of nickel carbides and other carbon species was checked. The correlation found between the surface atomic ratio Na/Si and the activity and selectivity of the ca…
Ambient carbon monoxide and daily mortality:a global time-series study in 337 cities
2021
Background Epidemiological evidence on short-term association between ambient carbon monoxide (CO) and mortality is inconclusive and limited to single cities, regions, or countries. Generalisation of results from previous studies is hindered by potential publication bias and different modelling approaches. We therefore assessed the association between short-term exposure to ambient CO and daily mortality in a multicity, multicountry setting. Methods We collected daily data on air pollution, meteorology, and total mortality from 337 cities in 18 countries or regions, covering various periods from 1979 to 2016. All included cities had at least 2 years of both CO and mortality data. We estimat…
Theoretical Basis Versus Clinical Practice of Oxygen Parameters of Blood
1996
Under optimal conditions all oxygen parameters of human blood are defined at a theoretical basis, accepted and understood by the clinicians, measured correctly by instruments of different manufacturers and, therefore, leading to clear diagnoses for the patients.
Optical Absorption of Excimer Laser‐Induced Dichlorine Monoxide in Silica Glass and Excitation of Singlet Oxygen Luminescence by Energy Transfer from…
2021
An optical absorption (OA) band of interstitial dichlorine monoxide molecules with peak at 4.7 eV and halfwidth 0.94 eV is identified in F2 laser - irradiated (photon energy=7.9 eV) synthetic silica glass bearing both interstitial O2 and Cl2 molecules. Alongside with intrinsic defects, this OA band can contribute to solarization of silica glasses produced from SiCl4. While the formation of ClClO is confirmed by its Raman signature, its structural isomer ClOCl may also contribute to this induced OA band. Thermal destruction of this band between 300C and 400C almost completely restores the pre-irradiation concentration of interstitial Cl2. An additional weak OA band at 3.5 eV is tentatively a…