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Zhan Catalyst
A Zhan catalyst is a type of ruthenium-based organometallic complex used in olefin metathesis. This class of chemicals is named after the chemist who first synthesized them, Zheng-Yun J. Zhan. These catalysts are ruthenium complexes with functionally substituted alkoxybenzylidene carbene ligands, which can be chemically bonded to the surface of resins, PEG chains, and polymers. Like the structurally similar Grubbs catalyst, Hoveyda-Grubbs catalyst, they contain an isopropoxystyrene moiety, but include an extra electron-withdrawing sulfonamide group attached to the carbon ''para'' to the phenol oxygen. Of the three catalysts, Zhan Catalyst-1B and -1C both contain a dimethylsulfonamide moiety attached to the aryl ring, while Zhan Catalyst-II is connected to a resin via a sulfonamide linker. History The Zhan catalysts were inspired by previous work in the olefin metathesis field. Robert H. Grubbs first reported the first and second generation of Ru catalysts in 1992, with good met ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ruthenium
Ruthenium is a chemical element; it has symbol Ru and atomic number 44. It is a rare transition metal belonging to the platinum group of the periodic table. Like the other metals of the platinum group, ruthenium is unreactive to most chemicals. Karl Ernst Claus, a Russian scientist of Baltic-German ancestry, discovered the element in 1844 at Kazan State University and named it in honor of Russia. (He used the Latin name '' Ruthenia'', which can have other meanings, but specifically stated that the element was named in honor of his "motherland".) Ruthenium is usually found as a minor component of platinum ores; the annual production has risen from about 19 tonnes in 2009 to some 35.5 tonnes in 2017. Most ruthenium produced is used in wear-resistant electrical contacts and thick-film resistors. A minor application for ruthenium is in platinum alloys and as a chemical catalyst. A new application of ruthenium is as the capping layer for extreme ultraviolet photoma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zhan Cat Ii
Zhan may refer to: Places * Zhan, Kurdistan, an Iranian village in Kurdistan Province * Zhan Rural District in Lorestan Province, Iran ** Zhan, Lorestan, a village in Zhan Rural District Names * Zhan (surname), several Chinese-language surnames Given name * Zhuge Zhan (227–263), Chinese politician * Zhang Zhan (born 1983), Chinese lawyer and citizen journalist * Gao Zhan (21st century), Chinese smuggler * Zhan Videnov (born 1959), Prime Minister of Bulgaria * Zhan Bush Zhan Viacheslavovich Bush ( born 1 April 1993) is a Russian figure skater. He is the 2013 Cup of Nice bronze medalist, a four-time medalist on the ISU Junior Grand Prix series, and 2011 Russian national senior bronze medalist. He placed 5th at ... (born 1993), Russian/Israeli figure skater See also * Zahn {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfonamides
In organic chemistry, the sulfonamide functional group (also spelled sulphonamide) is an organosulfur group with the Chemical structure, structure . It consists of a sulfonyl group () connected to an amine group (). Relatively speaking this group is unreactive. Because of the rigidity of the functional group, sulfonamides are typically crystalline; for this reason, the formation of a sulfonamide is a classic method to convert an amine into a crystalline derivative which can be identified by its melting point. Many important drugs contain the sulfonamide group. A sulfonamide (compound) is a chemical compound that contains this group. The general formula is or , where each R is some organic group; for example, "methanesulfonamide" (where R = methane, R' = R" = hydrogen) is . Any sulfonamide can be considered as derived from a sulfonic acid by replacing a hydroxyl group () with an amine group. In medicine, the term "sulfonamide" is sometimes used as a synonym for Sulfonamide (m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Catalysts
Catalysis () is the increase in reaction rate, rate of a chemical reaction due to an added substance known as a catalyst (). Catalysts are not consumed by the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recycles quickly, very small amounts of catalyst often suffice; mixing, surface area, and temperature are important factors in reaction rate. Catalysts generally react with one or more reactants to form reaction intermediate, intermediates that subsequently give the final reaction product, in the process of regenerating the catalyst. The rate increase occurs because the catalyst allows the reaction to occur by an alternative mechanism which may be much faster than the noncatalyzed mechanism. However the noncatalyzed mechanism does remain possible, so that the total rate (catalyzed plus noncatalyzed) can only increase in the presence of the catalyst and never decrease. Catalysis may be classified as either homogeneous catalysis, homogeneou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organoruthenium Compounds
Organoruthenium chemistry is the chemistry of organometallic compounds containing a carbon to ruthenium chemical bond. Several organoruthenium catalysts are of commercial interest and organoruthenium compounds have been considered for cancer therapy. The chemistry has some stoichiometric similarities with organoiron chemistry, as iron is directly above ruthenium in group 8 of the periodic table. The most important reagents for the introduction of ruthenium are ruthenium(III) chloride and triruthenium dodecacarbonyl. In its organometallic compounds, ruthenium is known to adopt oxidation states from −2 ( u(CO)4sup>2−) to +6 ( uN(Me)4sup>−). Most common are those in the +2 oxidation state, as illustrated below. File:Grubbs Catalyst 1st Generation.svg, 1st generation Grubbs catalyst File:ShvoCat.png, Shvo catalyst File:RuCymCl2.png, (cymene)ruthenium dichloride dimer File:Trirutheniumdodecacarbonyl.svg, triruthenium dodecacarbonyl. File:Chloro(cyclopentadienyl)bis(triph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zhan Ligand Synthesis
Zhan may refer to: Places * Zhan, Kurdistan, an Iranian village in Kurdistan Province * Zhan Rural District in Lorestan Province, Iran ** Zhan, Lorestan, a village in Zhan Rural District Names * Zhan (surname), several Chinese-language surnames Given name * Zhuge Zhan (227–263), Chinese politician * Zhang Zhan (born 1983), Chinese lawyer and citizen journalist * Gao Zhan (21st century), Chinese smuggler * Zhan Videnov (born 1959), Prime Minister of Bulgaria * Zhan Bush Zhan Viacheslavovich Bush ( born 1 April 1993) is a Russian figure skater. He is the 2013 Cup of Nice bronze medalist, a four-time medalist on the ISU Junior Grand Prix series, and 2011 Russian national senior bronze medalist. He placed 5th at ... (born 1993), Russian/Israeli figure skater See also * Zahn {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Journal Of Organic Chemistry
''The Journal of Organic Chemistry'', colloquially known as ''JOC'', is a peer-reviewed scientific journal for original contributions of fundamental research in all branches of theory and practice in organic and bioorganic chemistry. It is published by the publishing arm of the American Chemical Society, with 24 issues per year. According to the ''Journal Citation Reports'', the journal had a 2023 impact factor of 3.3 and it is the journal that received the most cites (100,091 in 2017) in the field of organic chemistry. According to Web of Knowledge (and as December 2012), eleven papers from the journal have received more than 1,000 citations, with the most cited paper having received 7,967 citations. The current editor-in-chief is Scott J. Miller from Yale University. Indexing ''J. Org. Chem.'' is currently indexed in: See also * Organic Letters *Organometallics ''Organometallics'' is a biweekly journal published by the American Chemical Society. Its area of focus is o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zhan Cat Synthesis
Zhan may refer to: Places * Zhan, Kurdistan, an Iranian village in Kurdistan Province * Zhan Rural District in Lorestan Province, Iran ** Zhan, Lorestan, a village in Zhan Rural District Names * Zhan (surname), several Chinese-language surnames Given name * Zhuge Zhan (227–263), Chinese politician * Zhang Zhan (born 1983), Chinese lawyer and citizen journalist * Gao Zhan (21st century), Chinese smuggler * Zhan Videnov (born 1959), Prime Minister of Bulgaria * Zhan Bush Zhan Viacheslavovich Bush ( born 1 April 1993) is a Russian figure skater. He is the 2013 Cup of Nice bronze medalist, a four-time medalist on the ISU Junior Grand Prix series, and 2011 Russian national senior bronze medalist. He placed 5th at ... (born 1993), Russian/Israeli figure skater See also * Zahn {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Angewandte Chemie International Edition
''Angewandte Chemie'' (, meaning "Applied Chemistry") is a weekly peer-reviewed scientific journal that is published by Wiley-VCH on behalf of the German Chemical Society (Gesellschaft Deutscher Chemiker). Publishing formats include feature-length reviews, short highlights, research communications, minireviews, essays, book reviews, meeting reviews, correspondences, corrections, and obituaries. This journal contains review articles covering all aspects of chemistry. According to the ''Journal Citation Reports'', the journal had a 2023 impact factor of 16.1. Editions The journal appears in two editions with separate volume and page numbering: a German edition, ''Angewandte Chemie'', and a fully English-language edition, ''Angewandte Chemie International Edition''. The editions are identical in content with the exception of occasional reviews of German-language books or German translations of IUPAC recommendations. Publication history In 1887, Ferdinand Fischer established the '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Olefin Metathesis
In organic chemistry, Olefin Metathesis or Alkene Metathesis is an organic reaction that entails the redistribution of fragments of alkenes (olefins) by the Bond cleavage, scission and regeneration of carbon-carbon double bonds. Because of the relative simplicity of olefin metathesis, it often creates fewer undesired by-products and hazardous wastes than alternative organic reactions. For their elucidation of the reaction mechanism and their discovery of a variety of highly active Catalysis, catalysts, Yves Chauvin, Robert H. Grubbs, and Richard R. Schrock were collectively awarded the 2005 Nobel Prize in Chemistry. Catalysts The reaction requires catalysis, metal catalysts. Most commercially important processes employ heterogeneous catalysis, heterogeneous catalysts. The heterogeneous catalysts are often prepared by in-situ activation of a metal halide (MClx) using organoaluminium or organotin compounds, e.g. combining MClx–EtAlCl2. A typical catalyst support is alumina. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Siegfried Blechert
Siegfried Blechert (born 1 March 1946 in Aalborg, Denmark) is a German chemist. Blechert studied chemistry at the University of Hannover, Germany and completed his PhD under the supervision of Ekkehard Winterfeldt in 1974. After a research stay with Pierre Potier in Gif-sur-Yvette, France, in 1981, he finished his habilitation at the University of Hannover in 1982 and there became lecturer in organic chemistry. In 1986 he took up a professorship at the University of Bonn. In 1990 he accepted the Chair of the Organic Chemistry Department at Technische Universität Berlin. His research interests include the development of new catalysts for olefin metathesis In organic chemistry, Olefin Metathesis or Alkene Metathesis is an organic reaction that entails the redistribution of fragments of alkenes (olefins) by the Bond cleavage, scission and regeneration of carbon-carbon double bonds. Because of the ..., novel synthetic methods, and the stereoselective synthesis of natural produ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amir H
Emir (; ' (), also transliterated as amir, is a word of Arabic origin that can refer to a male monarch, aristocrat, holder of high-ranking military or political office, or other person possessing actual or ceremonial authority. The title has a history of use in West Asia, East Africa, West Africa, Central Asia, and South Asia. In the modern era, when used as a formal monarchical title, it is roughly synonymous with "prince", applicable both to a son of a hereditary monarch, and to a reigning monarch of a sovereign principality, namely an emirate. The feminine form is emira ( '), with the same meaning as "princess". Prior to its use as a monarchical title, the term "emir" was historically used to denote a "commander", "general", or "leader" (for example, Amir al-Mu'min). In contemporary usage, "emir" is also sometimes used as either an honorary or formal title for the head of an Islamic, or Arab (regardless of religion) organisation or movement. Qatar and Kuwait are the only i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
