Definition & Betydelse | Engelska ordet OSMIUM

Definition av OSMIUM

1. osmium

Exempel på hur man kan använda OSMIUM i en mening

• The osmium atom exhibits double bonds to the four oxide ligands, resulting in a 16 electron complex.
• Gold, platinum, and the other platinum group metals (ruthenium, rhodium, palladium, osmium, iridium) are most often so classified.
• Bosch was also responsible for finding a more practical catalyst than the scarce osmium and expensive uranium being used by Haber.
• Sharpless asymmetric dihydroxylation (also called the Sharpless bishydroxylation) is the chemical reaction of an alkene with osmium tetroxide in the presence of a chiral quinine ligand to form a vicinal diol.
• Other precious metals include the platinum group metals: ruthenium, rhodium, palladium, osmium, iridium, and platinum, of which platinum is the most widely traded.
• Large reserves of platinum, rhodium, ruthenium, palladium, iridium, and osmium have been discovered in Tropojë.
• Another study used osmium tetroxide staining during freeze substitution, and showed that the endothelial glycocalyx could be up to 11 μm thick.
• In 1840, Claus, received a substantial amount of platinum ore samples for his studies from the Ural Mountains and the St Petersburg Mint and started working on chemistry and isolation of noble metals, in particular rhodium, iridium, osmium, and to a lesser extent, palladium and platinum.
• For example, the reduction of osmium hexafluoride to osmium pentafluoride with iodine is conducted in a solution in iodine pentafluoride:.
• This heterocyclic amine oxide and morpholine derivative is used in organic chemistry as a co-oxidant and sacrificial catalyst in oxidation reactions for instance in osmium tetroxide oxidations and the Sharpless asymmetric dihydroxylation or oxidations with TPAP.
• The Milas hydroxylation, Upjohn dihydroxylation, and Sharpless asymmetric dihydroxylation reactions all use osmium as the catalyst as well as varying secondary oxidizing agents.
• In terms of raw material shopping, this taxol molecule consists of the aforementioned Wieland-Miescher ketone, 2-methyl-3-pentanone, lithium aluminium hydride, osmium tetroxide, phenyllithium, pyridinium chlorochromate, the Corey-Chaykovsky reagent and acryloyl chloride.
• Oxidants can be regenerated by reduction of N-oxides, as in the case of regeneration of osmium tetroxide by N-methylmorpholine N-oxide in the Upjohn dihydroxylation.
• Scientist David Evans argued that as adamantium "is considered to be a very dense and indestructible metal" the most suitable real material to model it would be osmium, "the densest known metallic element".
• These include gold, iridium, silver, osmium, palladium, platinum, rhenium, rhodium, ruthenium and tungsten for transport back to Earth; iron, cobalt, manganese, molybdenum, nickel, aluminium, and titanium for construction; water and oxygen to sustain astronauts; as well as hydrogen, ammonia, and oxygen for use as rocket propellant.
• Some suitable negative stains include ammonium molybdate, uranyl acetate, uranyl formate, phosphotungstic acid, osmium tetroxide, osmium ferricyanide and auroglucothionate.
• The ruthenium tetroxide is very similar to osmium tetroxide; the ruthenium compound is a stronger oxidant which enables it to form deposits by reacting with other substances.
• Several variations on the method exist to increase contrast or selectivity in the type of neuron stained, and include additional impregnation in mercuric chloride solution (Golgi-Cox) or post-treatment with osmium tetroxide (Cajal or rapid Golgi).
• Osmiridium and iridosmine are natural alloys of the elements osmium and iridium, with traces of other platinum-group metals.
• Osmium pentafluoride is a tetramer in the solid state that can be prepared by reduction of osmium hexafluoride with iodine as a solution in iodine pentafluoride:.

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