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Willy Marckwald
Willy Marckwald (1864, Jakobskirch, Germany – 1942, Rolândia, Brazil) was a German chemist. He was nominated for the Nobel Prize in Chemistry in 1922 by Gustav Tammann and again in 1929 by Niels Bohr, Dirk Coster and George de Hevesy. Biography Marckwald studied at Berlin's Friedrich-Wilhelms-Universität and received there from the First Chemical Institute in 1886 his Promotierung under A. W. Hofmann with a dissertation on organic chemistry entitled ''Beitrag zur Kenntniss der Thialdehyde und Thialdine''. By his research on furans, Marckwald received his Habilitation in a very short time in 1889 under the supervision of A. W. Hofmann at Friedrich-Wilhelms-Universität Berlin. In 1899 Marckwald became one of the department heads at the Second Chemical Institute. He held this Privatdozent-level position until his age-related retirement in 1930. From 1928 to 1931 he was the board chair of the German Chemical Society. In 1890 Marckwald married Margarete Salomon (1871–190 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Willy Marckwald Ca 1900 Berlin
Willy or Willie is a masculine, male given name, often a diminutive form of William (given name), William or Wilhelm (name), Wilhelm, and occasionally a nickname. It may refer to: People Given name or nickname * Willie Aames (born 1960), American actor, television director, and screenwriter * Willie Allen (basketball) (born 1949), American basketball player and director of the Growing Power urban farming program * Willie Allen (racing driver) (born 1980), American racing driver * Willie Anderson (other) * Willie Apiata (born 1972), New Zealand Army soldier, only recipient of the Victoria Cross for New Zealand * Willie (footballer) (born 1993), Brazilian footballer Willie Hortencio Barbosa * Willy Böckl (1893–1975), Austrian world champion figure skater * Willy Bocklant (1941–1985), Belgian road racing cyclist * Willy Bogner, Sr. (1909–1977), German Nordic skier * Willy Bogner, Jr. (born 1942), German fashion designer and alpine skier * Willie Bosket (born 1962), Ame ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heterocyclic Chemistry
A heterocyclic compound or ring structure is a cyclic compound that has atoms of at least two different elements as members of its ring(s). Heterocyclic chemistry is the branch of organic chemistry dealing with the synthesis, properties, and applications of these heterocycles. Examples of heterocyclic compounds include all of the nucleic acids, the majority of drugs, most biomass (cellulose and related materials), and many natural and synthetic dyes. More than half of known compounds are heterocycles. 59% of US FDA-approved drugs contain nitrogen heterocycles. Classification The study of heterocyclic chemistry focuses especially on unsaturated derivatives, and the preponderance of work and applications involves unstrained 5- and 6-membered rings. Included are pyridine, thiophene, pyrrole, and furan. Another large class of heterocycles refers to those fused to benzene rings. For example, the fused benzene derivatives of pyridine, thiophene, pyrrole, and furan are quinol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1942 Deaths
Year 194 ( CXCIV) was a common year starting on Tuesday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Septimius and Septimius (or, less frequently, year 947 ''Ab urbe condita''). The denomination 194 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years. Events By place Roman Empire * Emperor Septimius Severus and Decimus Clodius Septimius Albinus Caesar become Roman Consuls. * Battle of Issus: Septimius Severus marches with his army (12 legions) to Cilicia, and defeats Pescennius Niger, Roman governor of Syria. Pescennius retreats to Antioch, and is executed by Severus' troops. * Septimius Severus besieges Byzantium (194–196); the city walls suffer extensive damage. Asia * Battle of Yan Province: Warlords Cao Cao and Lü Bu fight for control over Yan Province; the battle lasts for over 100 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1864 Births
Events January–March * January 13 – American songwriter Stephen Foster ("Oh! Susanna", "Old Folks at Home") dies aged 37 in New York City, leaving a scrap of paper reading "Dear friends and gentle hearts". His parlor song " Beautiful Dreamer" is published in March. * January 16 – Denmark rejects an Austrian-Prussian ultimatum to repeal the Danish Constitution, which says that Schleswig-Holstein is part of Denmark. * January 21 – New Zealand Wars: The Tauranga campaign begins. * February – John Wisden publishes '' The Cricketer's Almanack for the year 1864'' in England; it will go on to become the major annual cricket reference publication. * February 1 – Danish-Prussian War (Second Schleswig War): 57,000 Austrian and Prussian troops cross the Eider River into Denmark. * February 15 – Heineken brewery founded in Netherlands. * February 17 – American Civil War: The tiny Confederate hand-propelled submarine ''H. L. Hunl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Karl Andreas Hofmann
Karl Andreas Hofmann (2 April 1870 – 15 October 1940) was a German inorganic chemist. He is best known for his discovery of a family of clathrates which consist of a 2-D metal cyanide sheet, with every second metal also bound axially to two other ligands. These materials have been named ' Hofmann clathrates' in his honour. Works * ''Lehrbuch der Anorganischen Chemie'' . Vieweg, Braunschweig 2nd ed. 191Digital editionby the University and State Library Düsseldorf The University and State Library Düsseldorf (german: Universitäts- und Landesbibliothek Düsseldorf, abbreviated ULB Düsseldorf) is a central service institution of Heinrich Heine University. Along with Bonn and Münster, it is also one of th ... References 1870 births 1940 deaths 19th-century German chemists Inorganic chemists 20th-century German chemists Ludwig Maximilian University of Munich alumni University of Tübingen faculty Technical University of Berlin faculty Solid state chemists ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ionium
Thorium (90Th) has seven naturally occurring isotopes but none are stable. One isotope, 232Th, is ''relatively'' stable, with a half-life of 1.405×1010 years, considerably longer than the age of the Earth, and even slightly longer than the generally accepted age of the universe. This isotope makes up nearly all natural thorium, so thorium was considered to be mononuclidic. However, in 2013, IUPAC reclassified thorium as binuclidic, due to large amounts of 230Th in deep seawater. Thorium has a characteristic terrestrial isotopic composition and thus a standard atomic weight can be given. Thirty-one radioisotopes have been characterized, with the most stable being 232Th, 230Th with a half-life of 75,380 years, 229Th with a half-life of 7,917 years, and 228Th with a half-life of 1.92 years. All of the remaining radioactive isotopes have half-lives that are less than thirty days and the majority of these have half-lives that are less than ten minutes. One isotope, 229Th, has a nucl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polonium
Polonium is a chemical element with the symbol Po and atomic number 84. Polonium is a chalcogen. A rare and highly radioactive metal with no stable isotopes, polonium is chemically similar to selenium and tellurium, though its metallic character resembles that of its horizontal neighbors in the periodic table: thallium, lead, and bismuth. Due to the short half-life of all its isotopes, its natural occurrence is limited to tiny traces of the fleeting polonium-210 (with a half-life of 138 days) in uranium ores, as it is the penultimate daughter of natural uranium-238. Though slightly longer-lived isotopes exist, they are much more difficult to produce. Today, polonium is usually produced in milligram quantities by the neutron irradiation of bismuth. Due to its intense radioactivity, which results in the radiolysis of chemical bonds and radioactive self-heating, its chemistry has mostly been investigated on the trace scale only. Polonium was discovered in July 1898 by Marie SkÅ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enantioselective Synthesis
Enantioselective synthesis, also called asymmetric synthesis, is a form of chemical synthesis. It is defined by IUPAC as "a chemical reaction (or reaction sequence) in which one or more new elements of chirality are formed in a substrate molecule and which produces the stereoisomeric (enantiomeric or diastereomeric) products in unequal amounts." Put more simply: it is the synthesis of a compound by a method that favors the formation of a specific enantiomer or diastereomer. Enantiomers are stereoisomers that have opposite configurations at every chiral center. Diastereomers are stereoisomers that differ at one or more chiral centers. Enantioselective synthesis is a key process in modern chemistry and is particularly important in the field of pharmaceuticals, as the different enantiomers or diastereomers of a molecule often have different biological activity. Overview Many of the building blocks of biological systems such as sugars and amino acids are produced exclusively as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kinetic Resolution
In organic chemistry, kinetic resolution is a means of differentiating two enantiomers in a racemic mixture. In kinetic resolution, two enantiomers react with different reaction rates in a chemical reaction with a chiral catalyst or reagent, resulting in an enantioenriched sample of the less reactive enantiomer. As opposed to chiral resolution, kinetic resolution does not rely on different physical properties of diastereomeric products, but rather on the different chemical properties of the racemic starting materials. The enantiomeric excess (ee) of the unreacted starting material continually rises as more product is formed, reaching 100% just before full completion of the reaction. Kinetic resolution relies upon differences in reactivity between enantiomers or enantiomeric complexes. Kinetic resolution can be used for the preparation of chiral molecules in organic synthesis. Kinetic resolution reactions utilizing purely synthetic reagents and catalysts are much less common tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marckwald Assym Katayse (1864–1942), German chemist
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Marckwald is a surname. Notable people with the surname include: * Dorothy Marckwald (1898–1986), American interior designer * Wilhelm Marckwald, German actor and director * Willy Marckwald Willy Marckwald (1864, Jakobskirch, Germany – 1942, Rolândia, Brazil) was a German chemist. He was nominated for the Nobel Prize in Chemistry in 1922 by Gustav Tammann and again in 1929 by Niels Bohr, Dirk Coster and George de Hevesy. Biogra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heterocyclic Compound
A heterocyclic compound or ring structure is a cyclic compound that has atoms of at least two different elements as members of its ring(s). Heterocyclic chemistry is the branch of organic chemistry dealing with the synthesis, properties, and applications of these heterocycles. Examples of heterocyclic compounds include all of the nucleic acids, the majority of drugs, most biomass (cellulose and related materials), and many natural and synthetic dyes. More than half of known compounds are heterocycles. 59% of US FDA-approved drugs contain nitrogen heterocycles. Classification The study of heterocyclic chemistry focuses especially on unsaturated derivatives, and the preponderance of work and applications involves unstrained 5- and 6-membered rings. Included are pyridine, thiophene, pyrrole, and furan. Another large class of heterocycles refers to those fused to benzene rings. For example, the fused benzene derivatives of pyridine, thiophene, pyrrole, and furan are quinol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
