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Hermann Kolbe
Adolph Wilhelm Hermann Kolbe (27 September 1818 – 25 November 1884) was a major contributor to the birth of modern organic chemistry. He was a professor at Marburg and Leipzig. Kolbe was the first to apply the term synthesis in a chemical context, and contributed to the philosophical demise of vitalism through synthesis of the organic substance acetic acid from carbon disulfide, and also contributed to the development of structural theory. This was done via modifications to the idea of "radicals" and accurate prediction of the existence of secondary and tertiary alcohols, and to the emerging array of organic reactions through his Kolbe electrolysis of carboxylate salts, the Kolbe-Schmitt reaction in the preparation of aspirin and the Kolbe nitrile synthesis. After studies with Wöhler and Bunsen, Kolbe was involved with the early internationalization of chemistry through work in London (with Frankland). He was elected to the Royal Swedish Academy of Sciences, and won the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Göttingen
Göttingen (, , ; nds, Chöttingen) is a college town, university city in Lower Saxony, central Germany, the Capital (political), capital of Göttingen (district), the eponymous district. The River Leine runs through it. At the end of 2019, the population was 118,911. General information The origins of Göttingen lay in a village called ''Gutingi, ''first mentioned in a document in 953 AD. The city was founded northwest of this village, between 1150 and 1200 AD, and adopted its name. In Middle Ages, medieval times the city was a member of the Hanseatic League and hence a wealthy town. Today, Göttingen is famous for its old university (''Georgia Augusta'', or University of Göttingen, "Georg-August-Universität"), which was founded in 1734 (first classes in 1737) and became the most visited university of Europe. In 1837, seven professors protested against the absolute sovereignty of the House of Hanover, kings of Kingdom of Hanover, Hanover; they lost their positions, but be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vladimir Markovnikov
Vladimir Vasilyevich Markovnikov (russian: Влади́мир Васи́льевич Марко́вников), also spelled as Markownikoff ( – 11 February 1904), was a Russian chemist. Early life and education Markovnikov studied economics at the University of Kazan; during his studies, under the Russian cameral system, he also studied chemistry. Career After a conflict with that university, Markovnikov was appointed professor at the University of Odessa in 1871 and, two years later, at the University of Moscow, where he stayed the rest of his career. He was elected as a member to the American Philosophical Society in 1901. Work Markovnikov is best known for Markovnikov's rule, elucidated in 1869 to describe addition reactions of H-X (where 'X' represents a halogen) to alkenes. According to this rule, the nucleophilic X- adds to the carbon atom with fewer hydrogen atoms, while the proton adds to the carbon atom with more hydrogen atoms bonded to it. Thus, hydrogen chloride ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Synthesis
As a topic of chemistry, chemical synthesis (or combination) is the artificial execution of chemical reactions to obtain one or several products. This occurs by physical and chemical manipulations usually involving one or more reactions. In modern laboratory uses, the process is reproducible and reliable. A chemical synthesis involves one or more compounds (known as '' reagents'' or ''reactants'') that will experience a transformation when subjected to certain conditions. Various reaction types can be applied to formulate a desired product. This requires mixing the compounds in a reaction vessel, such as a chemical reactor or a simple round-bottom flask. Many reactions require some form of processing (" work-up") or purification procedure to isolate the final product. The amount produced by chemical synthesis is known as the ''reaction yield''. Typically, yields are expressed as a mass in grams (in a laboratory setting) or as a percentage of the total theoretical quantity that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leipzig University
Leipzig University (german: Universität Leipzig), in Leipzig in Saxony, Germany, is one of the world's oldest universities and the second-oldest university (by consecutive years of existence) in Germany. The university was founded on 2 December 1409 by Frederick I, Elector of Saxony and his brother William II, Margrave of Meissen, and originally comprised the four scholastic faculties. Since its inception, the university has engaged in teaching and research for over 600 years without interruption. Famous alumni include Gottfried Wilhelm von Leibniz, Johann Wolfgang von Goethe, Leopold von Ranke, Friedrich Nietzsche, Robert Schumann, Richard Wagner, Tycho Brahe, Georgius Agricola, Angela Merkel and ten Nobel laureates associated with the university. History Founding and development until 1900 The university was modelled on the University of Prague, from which the German-speaking faculty members withdrew to Leipzig after the Jan Hus crisis and the Decree of Kutná Hora. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Chemistry
Organic chemistry is a subdiscipline within chemistry involving the scientific study of the structure, properties, and reactions of organic compounds and organic materials, i.e., matter in its various forms that contain carbon atoms.Clayden, J.; Greeves, N. and Warren, S. (2012) ''Organic Chemistry''. Oxford University Press. pp. 1–15. . Study of structure determines their structural formula. Study of properties includes physical and chemical properties, and evaluation of chemical reactivity to understand their behavior. The study of organic reactions includes the chemical synthesis of natural products, drugs, and polymers, and study of individual organic molecules in the laboratory and via theoretical ( in silico) study. The range of chemicals studied in organic chemistry includes hydrocarbons (compounds containing only carbon and hydrogen) as well as compounds based on carbon, but also containing other elements, especially oxygen, nitrogen, sulfur, phosphorus (included in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Fellows Of The Royal Society J, K, L
About 8,000 fellows have been elected to the Royal Society of London since its inception in 1660. Below is a list of people who are or were Fellow of the Royal Society, Fellow or Foreign Member of the Royal Society. The date of election to the fellowship follows the name. Dates in brackets relate to an award or event associated with the person. The Society maintains complete online list. This list is complete up to and including 2019. List of fellows J K L Foreign members J K L References External links The Royal Societywebsite Complete List of Royal Society Fellows 1660–2007in pdf format Fellows index of MacTutor History of Mathematics archive, MacTutor History of Mathematics {{Fellows of the Royal Society Fellows of the Royal Society Lists of fellows of the Royal Society ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Davy Medal
The Davy Medal is awarded by the Royal Society of London "for an outstandingly important recent discovery in any branch of chemistry". Named after Humphry Davy, the medal is awarded with a monetary gift, initially of £1000 (currently £2000). History The medal was first awarded in 1877 to Robert Wilhelm Bunsen and Gustav Robert Kirchhoff "for their researches & discoveries in spectrum analysis", and has since been awarded 140 times. The medal is awarded annually and, unlike other Royal Society medals (such as the Hughes), has been awarded without interruption since its inception. The medal has been awarded to multiple individuals in the same year: in 1882, for example, it was awarded to Dmitri Mendeleev and Julius Lothar Meyer "for their discovery of the periodic relations of the atomic weights"; in 1883 to Marcellin Berthelot and Julius Thomsen "for their researches in thermo-chemistry"; in 1893 to Jacobus Henricus van 't Hoff and Joseph Achille Le Bel "In recognition of thei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kolbe Nitrile Synthesis
The Kolbe nitrile synthesis is a method for the preparation of alkyl nitriles by reaction of the corresponding alkyl halide with a metal cyanide. A side product for this reaction is the formation of an isonitrile because the cyanide ion is an ambident nucleophile and according to Kornblum's rule is capable of reacting with either carbon or nitrogen. The reaction is named after Hermann Kolbe. :\underset + \underset -> \underset + \underset The ratio in which both isomers form depends on the solvent and the reaction mechanism. With the application of alkali cyanides such as sodium cyanide and polar solvents the reaction type is an SN2 reaction whereby the alkylhalide is attacked by the more nucleophilic carbon atom of the cyanide ion. This type of reaction together with dimethyl sulfoxide as a solvent is a convenient method for the synthesis of nitriles. The use of DMSO was a major advancement in the development of this reaction, as it works for more sterically hindered electrophi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kolbe–Schmitt Reaction
The Kolbe–Schmitt reaction or Kolbe process (named after Hermann Kolbe and Rudolf Schmitt) is a carboxylation chemical reaction that proceeds by heating sodium phenoxide (the sodium salt of phenol) with carbon dioxide under pressure (100 atm, 125 °C), then treating the product with sulfuric acid. The final product is an aromatic hydroxy acid which is also known as salicylic acid (the precursor to aspirin). 500px, center, The Kolbe–Schmitt reaction By using potassium hydroxide, 4-hydroxybenzoic acid is accessible, an important precursor for the versatile paraben class of biocides used e.g. in personal care products. The methodology is also used in the industrial synthesis of 3-hydroxy-2-naphthoic acid; the regiochemistry of the carboxylation in this case is sensitive to temperature.. Reaction mechanism The Kolbe–Schmitt reaction proceeds via the nucleophilic addition of a phenoxide, classically sodium phenoxide (NaOC6H5), to carbon dioxide to give the salicylate. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kolbe Electrolysis
__NOTOC__ The Kolbe electrolysis or Kolbe reaction is an organic reaction named after Hermann Kolbe. The Kolbe reaction is formally a decarboxylative dimerisation of two carboxylic acids (or carboxylate ions). The overall reaction is: : If a mixture of two different carboxylates are used, all combinations of them are generally seen as the organic product structures: : 3 R1COO− + 3 R2COO− → R1−R1 + R1−R2 + R2−R2 + 6 CO2 + 6 e− The reaction mechanism involves a two-stage radical process: electrochemical decarboxylation gives a radical intermediate, which combine to form a covalent bond. As an example, electrolysis of acetic acid yields ethane and carbon dioxide: :CH3COOH → CH3COO− → CH3COO· → CH3· + CO2 :2CH3· → CH3CH3 Another example is the synthesis of 2,7-dimethyl-2,7-dinitrooctane from 4-methyl-4-nitrovaleric acid: : Further reading * * See also * Electrosynthesis * Wurtz reaction In organic chemistry, the Wurtz reaction, named a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frederick Guthrie
Frederick Guthrie FRS FRSE (15 October 1833 – 21 October 1886) was a British physicist and chemist and academic author. He was the son of Alexander Guthrie, a London tradesman, and the younger brother of mathematician Francis Guthrie. Along with William Fletcher Barrett he founded the Physical Society of London (now the Institute of Physics) in 1874 and was president of the society from 1884 until 1886. He believed that science should be based on experimentation rather than discussion. Academic career His academic career started at University College, London, where he studied for three years. He studied chemistry under Thomas Graham and Alexander William Williamson and mathematics under Augustus De Morgan. In 1852, he submitted his brother Francis's observations to De Morgan. In 1854 Guthrie went to Heidelberg to study under Robert Bunsen and then in 1855 obtained a PhD at the University of Marburg under Adolph Wilhelm Hermann Kolbe. In 1856 he joined Edward Frankland, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maxwell Simpson
Maxwell Simpson (15 March 1815 – 26 February 1902) was an eminent Irish chemist. Life He was born in Beach Hill, County Armagh, Ireland, son of Thomas Simpson. He attended Dr. Henderson's school at Newry before continuing to Trinity College, Dublin in 1832. He graduated in 1837 and travelled on the continent. After attending a lecture in Paris by Dumas on chemistry he decided to study that subject, which he did at University College, London. In 1847 he became lecturer in chemistry at the Park Street Medical School (later Ledwich School of Medicine) in Dublin. Upon closure of that school he lectured at the Peter St. School of Medicine. He then took three years leave of absence in order to study in Germany, returned to Dublin in 1854, spent two further years in Paris and returned again in 1860. At this point he built a laboratory in his Dublin home in which he worked for the next seven years. During this early part of his life he had started making the discoveries that placed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
