نتایج جستجو برای: iridium compounds
تعداد نتایج: 230621 فیلتر نتایج به سال:
47 The interpretation of the Cretaceous-Paleogene (K-Pg) iridium anomaly – and other 48 impact ejecta – as the result of a single, large asteroid impact has been the subject of much 49 debate, in part due to the distribution of impact markers beyond the narrow confines of the K-Pg 50 boundary sedimentary layer. Here, we revisit the hypothesized processes leading to the shape of 51 K-Pg iridium ...
Highly unsaturated mono(N-heterocyclic carbene) Ir(iii) systems have been targeted via ligand abstraction protocols. Hydrogenation of Ir(IPr)(cod)Cl (1a) leads to the formation of the highly reactive (fluxional) trimer [Ir(IPr)(H)(2)Cl](3), while the related IMes system undergoes further C-H bond activation. Chloride abstraction from 1a prior to hydrogenation allows access to sources of the 12-...
The iridium complex [Cp*Ir(H2O)3](SO4) was used as an organometallic source for the electrodeposition of iridium oxide onto Fe2O3. The new iridium-containing electrode allowed us to study the coupling between the photocatalytic properties of hematite and the electrocatalytic properties of the iridium-based material. A cathodic shift of the photocurrent for water oxidation upon electrodeposition...
Catalytic total oxidation of noxious volatile organic compounds (VOCs) is an important process to remove these from the atmosphere. This first systematic study influence support on activity iridium oxide supported catalysts for VOCs. Iridium titania, ?-alumina, silica and zeolites have been prepared using different calcination temperatures. The short chain alkanes their mixtures has evaluated p...
The production of enantiopure chiral compounds is important for pharmaceutical and agrochemical industries because enantiomers can exhibit distinct biological activities. Therefore, processes that directly produce the desired enantiomer are desirable. First reported by Knowles, Horner et al. in 1968, catalytic asymmetric hydrogenation of unsaturated compounds such as olefins, ketones, and imine...
Materials that are strong at progressively higher temperatures are sought for use in aircraft engines, in order that operating temperatures, and thereby efficiency and performance, can be increased. Intermetallic compounds with high melting temperatures have the promise of higher strength and elastic stiffness while hot, but in most cases they suffer from extreme brittleness at room temperature...
Finding a safe and efficient carrier of hydrogen is a major challenge. Recently, hydrogenated organic compounds have been studied as hydrogen storage materials because of their ability to stably and reversibly store hydrogen by forming chemical bonds; however, these compounds often suffer from safety issues and are usually hydrogenated with hydrogen at high pressure and/or temperature. Here we ...
The organometallic chemistry of 4d and 5d transition metals has been vastly dominated by closed-shell states. reactivity their metalloradical species is though remarkable, albeit yet poorly understood with limited mechanistic investigations available. In this work we report the synthesis characterization two mononuclear IrII species, including first dinitrogen adduct. These compounds activate d...
To assist in nuclear forensic investigations, new techniques are required to evaluate radioactive materials that may be discovered outside of regulatory control. Using a recently developed pressure digestion method for iridium powder, assessments have been made of this techniques suitability for undertaking iridium target material evaluations. In addition to determining the reaction conditions ...
The past decade has witnessed rapid progress in the field of asymmetric hydrogenation of aromatic compounds, a transformation, which is regarded as one of the most straightforward means for accessing enantiopure cyclic compounds. Extensive research has significantly expanded the substrate scope of this reaction, and substrates such as quinolines, quinoxalines, indoles, furans, pyrroles, pyridin...
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