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Hans Meerwein
Hans Meerwein (May 20, 1879 in Hamburg, Germany – October 24, 1965 in Marburg, Germany) was a German chemist. Several reactions and reagents bear his name, most notably the Meerwein–Ponndorf–Verley reduction, the Wagner–Meerwein rearrangement, the Meerwein arylation reaction, and Meerwein's salt. Life and work His father was the architect, Wilhelm Emil Meerwein. He originally trained to be a chemistry technician or 'chemotechnician' at the Fresenius University of Applied Sciences (between 1898 and 1900) before studying for a chemistry degree at the University of Bonn. After finishing his PhD with Richard Anschütz he worked at the University of Berlin, before returning to Bonn where he became professor in 1914. From 1922 till 1928 he was professor for organic chemistry at the University of Königsberg. The last change in his academic career was to the University of Marburg. The war devastated the Institute and Meerwein was planning the rebuilding which was finished ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hamburg
(male), (female) en, Hamburger(s), Hamburgian(s) , timezone1 = Central (CET) , utc_offset1 = +1 , timezone1_DST = Central (CEST) , utc_offset1_DST = +2 , postal_code_type = Postal code(s) , postal_code = 20001–21149, 22001–22769 , area_code_type = Area code(s) , area_code = 040 , registration_plate = , blank_name_sec1 = GRP (nominal) , blank_info_sec1 = €123 billion (2019) , blank1_name_sec1 = GRP per capita , blank1_info_sec1 = €67,000 (2019) , blank1_name_sec2 = HDI (2018) , blank1_info_sec2 = 0.976 · 1st of 16 , iso_code = DE-HH , blank_name_sec2 = NUTS Region , blank_info_sec2 = DE6 , website = , footnotes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isobornyl
Borneol is a bicyclic organic compound and a terpene derivative. The hydroxyl group in this compound is placed in an '' endo'' position. The exo diastereomer is called isoborneol. Being chiral, borneol exists as enantiomers, both of which are found in nature. Reactions Borneol is oxidized to the ketone ( camphor). Occurrence The compound was named in 1842 by the French chemist Charles Frédéric Gerhardt. Borneol can be found in several species of ''Heterotheca'', '' Artemisia'', ''Rosmarinus officinalis'' (rosemary) '' Dipterocarpaceae'', ''Blumea balsamifera'' and '' Kaempferia galanga''. It is one of the chemical compounds found in castoreum. This compound is gathered from the beaver's plant food. Synthesis Borneol can be synthesized by reduction of camphor by the Meerwein–Ponndorf–Verley reduction (a reversible process). Reduction of camphor with sodium borohydride (fast and irreversible) gives instead the diastereomer isoborneol. : Uses Whereas ''d''-borneo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Bonn Alumni
A university () is an institution of higher (or tertiary) education and research which awards academic degrees in several academic disciplines. Universities typically offer both undergraduate and postgraduate programs. In the United States, the designation is reserved for colleges that have a graduate school. The word ''university'' is derived from the Latin ''universitas magistrorum et scholarium'', which roughly means "community of teachers and scholars". The first universities were created in Europe by Catholic Church monks. The University of Bologna (''Università di Bologna''), founded in 1088, is the first university in the sense of: *Being a high degree-awarding institute. *Having independence from the ecclesiastic schools, although conducted by both clergy and non-clergy. *Using the word ''universitas'' (which was coined at its foundation). *Issuing secular and non-secular degrees: grammar, rhetoric, logic, theology, canon law, notarial law.Hunt Janin: "The university ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1965 Deaths
Events January–February * January 14 – The Prime Minister of Northern Ireland and the Taoiseach of the Republic of Ireland meet for the first time in 43 years. * January 20 ** Lyndon B. Johnson is sworn in for a full term as President of the United States. ** Indonesian President Sukarno announces the withdrawal of the Indonesian government from the United Nations. * January 30 – The state funeral of Sir Winston Churchill takes place in London with the largest assembly of dignitaries in the world until the 2005 funeral of Pope John Paul II. * February 4 – Trofim Lysenko is removed from his post as director of the Institute of Genetics at the Academy of Sciences in the Soviet Union. Lysenkoist theories are now treated as pseudoscience. * February 12 ** The African and Malagasy Common Organization ('; OCAM) is formed as successor to the Afro-Malagasy Union for Economic Cooperation ('; UAMCE), formerly the African and Malagasy Union ('; UAM ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1879 Births
Events January–March * January 1 – The Specie Resumption Act takes effect. The United States Note is valued the same as gold, for the first time since the American Civil War. * January 11 – The Anglo-Zulu War begins. * January 22 – Anglo-Zulu War – Battle of Isandlwana: A force of 1,200 British soldiers is wiped out by over 20,000 Zulu warriors. * January 23 – Anglo-Zulu War – Battle of Rorke's Drift: Following the previous day's defeat, a smaller British force of 140 successfully repels an attack by 4,000 Zulus. * February 3 – Mosley Street in Newcastle upon Tyne (England) becomes the world's first public highway to be lit by the electric incandescent light bulb invented by Joseph Swan. * February 8 – At a meeting of the Royal Canadian Institute, engineer and inventor Sandford Fleming first proposes the global adoption of standard time. * March 3 – United States Geological Survey is founded. * March 11 – ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Otto Hahn Prize
The Otto Hahn Prize is awarded biennially jointly by the Society of German Chemists (), the German Physical Society () and the city of Frankfurt am Main for outstanding achievement in the field of chemistry, physics or applied engineering science. It was established in 2005 by the merger of the previous Otto Hahn Prize for Chemistry and Physics and the Otto Hahn Prize of the City of Frankfurt am Main. The award is presented in the St. Paul's Church, Frankfurt am Main. The award named after the German nuclear scientist and Nobel laureate Otto Hahn and consists of a gold medal and a prize of 50,000 euros. It is awarded alternatively for Chemistry and Physics. Recipients: Otto Hahn Prize SourceSociety of German Chemists * 2005: Theodor W. Hänsch (physics) * 2007: Gerhard Ertl (chemistry) * 2009: Stefan Hell (physics) * 2011: Manfred T. Reetz (chemistry) * 2013: Ferenc Krausz (physics) * 2015: Jürgen Troe (chemistry) * 2017: (physics) * 2019: , Stuttgart (chemistry) * 2021 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Josef Houben
Heinrich Hubert Maria Josef Houben (27 October 1875, in Waldfeucht ( Rheinland) Germany – 28 June 1940, in Tübingen) was a German chemist. He made achievements within ketone synthesis, terpenes, and camphor studies. After being wounded several times on the front lines in World War I, Houben was made head of the war laboratory. He improved the Hoesch reaction which is now normally called Houben-Hoesch reaction. Houben organized and made a major rework of the book Methods of Organic Chemistry which is now referred to as Houben-Weyl Methods of Organic Chemistry. Life Houben studied at the University of Bonn and changed his subjects from mathematics and astronomy to chemistry under the influence of August Kekulé. He received his Ph.D. for work with Julius Bredt in 1898, and they collaborated on the initial 1902 publication of what became known as Bredt's Rule. After some time at the University of Aachen and University of Bonn Houben joined the laboratory of Emil Fischer at t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydride
In chemistry, a hydride is formally the anion of hydrogen( H−). The term is applied loosely. At one extreme, all compounds containing covalently bound H atoms are called hydrides: water (H2O) is a hydride of oxygen, ammonia is a hydride of nitrogen, etc. For inorganic chemists, hydrides refer to compounds and ions in which hydrogen is covalently attached to a less electronegative element. In such cases, the H centre has nucleophilic character, which contrasts with the protic character of acids. The hydride anion is very rarely observed. Almost all of the elements form binary compounds with hydrogen, the exceptions being He, Ne, Ar, Kr, Pm, Os, Ir, Rn, Fr, and Ra. Exotic molecules such as positronium hydride have also been made. Bonds Bonds between hydrogen and the other elements range from highly to somewhat covalent. Some hydrides, e.g. boron hydrides, do not conform to classical electron-counting rules and the bonding is described in terms of multi-ce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isobornyl Chloride
Borneol is a bicyclic organic compound and a terpene derivative. The hydroxyl group in this compound is placed in an '' endo'' position. The exo diastereomer is called isoborneol. Being chiral, borneol exists as enantiomers, both of which are found in nature. Reactions Borneol is oxidized to the ketone ( camphor). Occurrence The compound was named in 1842 by the French chemist Charles Frédéric Gerhardt. Borneol can be found in several species of ''Heterotheca'', '' Artemisia'', ''Rosmarinus officinalis'' (rosemary) '' Dipterocarpaceae'', ''Blumea balsamifera'' and '' Kaempferia galanga''. It is one of the chemical compounds found in castoreum. This compound is gathered from the beaver's plant food. Synthesis Borneol can be synthesized by reduction of camphor by the Meerwein–Ponndorf–Verley reduction (a reversible process). Reduction of camphor with sodium borohydride (fast and irreversible) gives instead the diastereomer isoborneol. : Uses Whereas ''d''-borneo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Racemization
In chemistry, racemization is a conversion, by heat or by chemical reaction, of an optically active compound into a racemic (optically inactive) form. This creates a 1:1 molar ratio of enantiomers and is referred too as a racemic mixture (i.e. contain equal amount of (+) and (−) forms). Plus and minus forms are called Dextrorotation and levorotation. The D and L enantiomers are present in equal quantities, the resulting sample is described as a racemic mixture or a racemate. Racemization can proceed through a number of different mechanisms, and it has particular significance in pharmacology as different enantiomers may have different pharmaceutical effects. Stereochemistry Chiral molecules have two forms (at each point of asymmetry), which differ in their optical characteristics: The ''levorotatory form'' (the ''(−)-form'') will rotate counter-clockwise on the plane of polarization of a beam of light, whereas the ''dextrorotatory'' form (the ''(+)-form'') will rotate clockwi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbocation
A carbocation is an ion with a positively charged carbon atom. Among the simplest examples are the methenium , methanium and vinyl cations. Occasionally, carbocations that bear more than one positively charged carbon atom are also encountered (e.g., ethylene dication ). Until the early 1970s, all carbocations were called ''carbonium ions''. In the present-day definition given by the IUPAC, a carbocation is any even-electron cation with significant partial positive charge on a carbon atom. They are further classified in two main categories according to the coordination number of the charged carbon: three in the carbenium ions and five in the carbonium ions. This nomenclature was proposed by G. A. Olah. Carbonium ions, as originally defined by Olah, are characterized by a three-center two-electron delocalized bonding scheme and are essentially synonymous with so-called 'non-classical carbocations', which are carbocations that contain bridging C–C or C–H σ-bonds. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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