Concept
Palladium
Related concepts (38)
Electrical contact
An electrical contact is an electrical circuit component found in electrical switches, relays, connectors and circuit breakers. Each contact is a piece of electrically conductive material, typically metal. When a pair of contacts touch, they can pass an electrical current with a certain contact resistance, dependent on surface structure, surface chemistry and contact time; when the pair is separated by an insulating gap, then the pair does not pass a current.
Wacker process
The Wacker process or the Hoechst-Wacker process (named after the chemical companies of the same name) refers to the oxidation of ethylene to acetaldehyde in the presence of palladium(II) chloride and copper(II) chloride as the catalyst. This chemical reaction was one of the first homogeneous catalysis with organopalladium chemistry applied on an industrial scale. The Wacker reaction was first reported by Smidt et al. The development of the chemical process now known as the Wacker process began in 1956 at Wacker Chemie.
Tris(dibenzylideneacetone)dipalladium(0)
Tris(dibenzylideneacetone)dipalladium(0) or [Pd2(dba)3] is an organopalladium compound. The compound is a complex of palladium(0) with dibenzylideneacetone (dba). It is a dark-purple/brown solid, which is modestly soluble in organic solvents. Because the dba ligands are easily displaced, the complex is used as a homogeneous catalyst in organic synthesis. First reported in 1970, it is prepared from dibenzylideneacetone and sodium tetrachloropalladate.
Organopalladium chemistry
Organopalladium chemistry is a branch of organometallic chemistry that deals with organic palladium compounds and their reactions. Palladium is often used as a catalyst in the reduction of alkenes and alkynes with hydrogen. This process involves the formation of a palladium-carbon covalent bond. Palladium is also prominent in carbon-carbon coupling reactions, as demonstrated in tandem reactions. 1873 - A. N. Zaitsev reports reduction of benzophenone over palladium with hydrogen.
Hiyama coupling
The Hiyama coupling is a palladium-catalyzed cross-coupling reaction of organosilanes with organic halides used in organic chemistry to form carbon–carbon bonds (C-C bonds). This reaction was discovered in 1988 by Tamejiro Hiyama and Yasuo Hatanaka as a method to form carbon-carbon bonds synthetically with chemo- and regioselectivity. The Hiyama coupling has been applied to the synthesis of various natural products.
Bullion
Bullion is non-ferrous metal that has been refined to a high standard of elemental purity. The term is ordinarily applied to bulk metal used in the production of coins and especially to precious metals such as gold and silver. It comes from the Anglo-Norman term for a melting-house where metal was refined, and earlier from French bouillon, "boiling". Although precious metal bullion is no longer used to make coins for general circulation, it continues to be held as an investment with a reputation for stability in periods of economic uncertainty.
Asymmetric hydrogenation
Asymmetric hydrogenation is a chemical reaction that adds two atoms of hydrogen to a target (substrate) molecule with three-dimensional spatial selectivity. Critically, this selectivity does not come from the target molecule itself, but from other reagents or catalysts present in the reaction. This allows spatial information (what chemists refer to as chirality) to transfer from one molecule to the target, forming the product as a single enantiomer.
Siberian Traps
The Siberian Traps (Sibirskiye trappy) is a large region of volcanic rock, known as a large igneous province, in Siberia, Russia. The massive eruptive event that formed the traps is one of the largest known volcanic events in the last 500 million years. The eruptions continued for roughly two million years and spanned the Permian–Triassic boundary, or P–T boundary, which occurred around 251.9 million years ago. The Siberian Traps are believed to be the primary cause of the Permian–Triassic extinction event, the most severe extinction event in the geologic record.