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August Wilhelm Von Hofmann
August Wilhelm von Hofmann (8 April 18185 May 1892) was a German chemist who made considerable contributions to organic chemistry. His research on aniline helped lay the basis of the aniline-dye industry, and his research on coal tar laid the groundwork for his student Charles Mansfield's practical methods for extracting benzene and toluene and converting them into nitro compounds and amines. Hofmann's discoveries include formaldehyde, hydrazobenzene, the isonitriles, and allyl alcohol. He prepared three ethylamines and tetraethylammonium compounds and established their structural relationship to ammonia. After studying under Justus von Liebig at the University of Giessen, Hofmann became the first director of the Royal College of Chemistry, now part of Imperial College London, in 1845. In 1865 he returned to Germany to accept a position at the University of Berlin as a teacher and researcher. After his return he co-founded the German Chemical Society (''Deutsche Chemische Gese ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Giessen
Giessen, spelled Gießen in German (), is a town in the German state (''Bundesland'') of Hesse, capital of both the district of Giessen and the administrative region of Giessen. The population is approximately 90,000, with roughly 37,000 university students. The name comes from ''Giezzen'', as it was first referred to in 1197, which refers to the position of the town between several rivers, lakes and streams. The largest river in Giessen is the Lahn, which divides the town in two parts (west and east), roughly north of Frankfurt am Main. Giessen is also home to the University of Giessen. In 1969, the town hosted the ninth ''Hessentag'' state festival. History Giessen came into being as a moated castle in 1152 built by Count Wilhelm von Gleiberg, although the history of the community in the northeast and in today's suburb called "Wieseck" dates back to 775. The town became part of Hesse-Marburg in 1567, passing to Hesse-Darmstadt in 1604. The University of Giessen was founded i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
William Henry Perkin
Sir William Henry Perkin (12 March 1838 – 14 July 1907) was a British chemist and entrepreneur best known for his serendipitous discovery of the first commercial synthetic organic dye, mauveine, made from aniline. Though he failed in trying to synthesise quinine for the treatment of malaria, he became successful in the field of dyes after his first discovery at the age of 18. Perkin set up a factory to produce the dye industrially. Lee Blaszczyk, professor of business history at the University of Leeds, states, "By laying the foundation for the synthetic organic chemicals industry, Perkin helped to revolutionize the world of fashion." Early years William Perkin was born in the East End of London, the youngest of the seven children of George Perkin, a successful carpenter. His mother, Sarah, was of Scottish descent and moved to East London as a child.UXL Encyclopedia of World Biography (2003). Accessed 18 March 2008. He was baptized in the Anglican parish church of St ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coal Tar
Coal tar is a thick dark liquid which is a by-product of the production of coke and coal gas from coal. It is a type of creosote. It has both medical and industrial uses. Medicinally it is a topical medication applied to skin to treat psoriasis and seborrheic dermatitis (dandruff). It may be used in combination with ultraviolet light therapy. Industrially it is a railroad tie preservative and used in the surfacing of roads. Coal tar was listed as a known human carcinogen in the first Report on Carcinogens from the U.S. Federal Government. Coal tar was discovered circa 1665 and used for medical purposes as early as the 1800s. Circa 1850, the discovery that it could be used as the main ingredient in synthetic dyes engendered an entire industry. It is on the World Health Organization's List of Essential Medicines. Coal tar is available as a generic medication and over the counter. Side effects include skin irritation, sun sensitivity, allergic reactions, and skin discoloration. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aniline
Aniline is an organic compound with the formula C6 H5 NH2. Consisting of a phenyl group attached to an amino group, aniline is the simplest aromatic amine In organic chemistry, an aromatic amine is an organic compound consisting of an aromatic ring attached to an amine. It is a broad class of compounds that encompasses aniline Aniline is an organic compound with the formula C6 H5 NH2. Consi .... It is an industrially significant Commodity chemicals, commodity chemical, as well as a versatile starting material for fine chemical synthesis. Its main use is in the manufacture of precursors to polyurethane, dyes, and other industrial chemicals. Like most volatile amines, it has the odor of rotten fish. It Combustion, ignites readily, burning with a smoky flame characteristic of aromatic compounds. It is toxic to humans. Relative to benzene, it is electron-rich. It thus participates more rapidly in electrophilic aromatic substitution reactions. Likewise, it is also prone ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemist
A chemist (from Greek ''chēm(ía)'' alchemy; replacing ''chymist'' from Medieval Latin ''alchemist'') is a scientist trained in the study of chemistry. Chemists study the composition of matter and its properties. Chemists carefully describe the properties they study in terms of quantities, with detail on the level of molecules and their component atoms. Chemists carefully measure substance proportions, chemical reaction rates, and other chemical properties. In Commonwealth English, pharmacists are often called chemists. Chemists use their knowledge to learn the composition and properties of unfamiliar substances, as well as to reproduce and synthesize large quantities of useful naturally occurring substances and create new artificial substances and useful processes. Chemists may specialize in any number of subdisciplines of chemistry. Materials scientists and metallurgists share much of the same education and skills with chemists. The work of chemists is often related to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Albert Medal (Royal Society Of Arts)
The Albert Medal of the Royal Society of Arts (RSA) was instituted in 1864 as a memorial to Prince Albert, who had been President of the Society for 18 years. It was first awarded in 1864 for "distinguished merit in promoting Arts, Manufactures and Commerce". In presenting the Medal, the Society now looks to acknowledge individuals, organizations and groups that lead progress and create positive change within contemporary society in areas that are linked closely to the Society's broad agenda. Through the Albert Medal, the Society acknowledges the creativity and innovation of those that work to tackle some of the world's intractable problems. Each year, the RSA identifies issues by asking the Society's Fellowship to suggest problems and subjects linked to the Society's programme. These proposals are reviewed and recommendations made to the Trustees and Council, who are responsible for selecting one upon which the Fellowship will be asked to nominate worthy recipients. Full list ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Faraday Lectureship Prize
The Faraday Lectureship Prize, previously known simply as the Faraday Lectureship, is awarded once every two years (approximately) by the Royal Society of Chemistry for "exceptional contributions to physical or theoretical chemistry".. Named after Michael Faraday, the first Faraday Lecture was given in 1869, two years after Faraday's death, by Jean-Baptiste Dumas.. As of 2009, the prize was worth £5000, with the recipient also receiving a medal and a certificate. As the name suggests, the recipient also gives a public lecture describing his or her work. Winners SourceRSC * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * See also * List of chemistry awards This list of chemistry awards is an index to articles about notable awards for chemistry. It includes awards by the Royal Society of Chemistry, the American Chemical Society, the Society of Chemical Industry and awards by other organizations ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copley Medal
The Copley Medal is an award given by the Royal Society, for "outstanding achievements in research in any branch of science". It alternates between the physical sciences or mathematics and the biological sciences. Given every year, the medal is the oldest Royal Society medal awarded and the oldest surviving scientific award in the world, having first been given in 1731 to Stephen Gray (scientist), Stephen Gray, for "his new Electrical Experiments: – as an encouragement to him for the readiness he has always shown in obliging the Society with his discoveries and improvements in this part of Natural Knowledge". __TOC__ History The medal was created following a donation of Pound sterling, £100 to be used for carrying out experiments by Sir Godfrey Copley, 2nd Baronet, Sir Godfrey Copley, for which the interest on the amount was used for several years. The conditions for the medal have been changed several times; in 1736, it was suggested that "a medal or other honorary prize s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Royal Medal
The Royal Medal, also known as The Queen's Medal and The King's Medal (depending on the gender of the monarch at the time of the award), is a silver-gilt medal, of which three are awarded each year by the Royal Society, two for "the most important contributions to the advancement of natural knowledge" and one for "distinguished contributions in the applied sciences", done within the Commonwealth of Nations. Background The award was created by George IV of the United Kingdom, George IV and awarded first during 1826. Initially there were two medals awarded, both for the most important discovery within the year previous, a time period which was lengthened to five years and then shortened to three. The format was endorsed by William IV of the United Kingdom, William IV and Victoria of the United Kingdom, Victoria, who had the conditions changed during 1837 so that mathematics was a subject for which a Royal Medal could be awarded, albeit only every third year. The conditions were chang ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ball-and-stick Model
In chemistry, the ball-and-stick model is a molecular model of a chemical substance which displays both the three-dimensional position of the atoms and the bonds between them. The atoms are typically represented by spheres, connected by rods which represent the bonds. Double and triple bonds are usually represented by two or three curved rods, respectively, or alternately by correctly positioned sticks for the sigma and pi bonds. In a good model, the angles between the rods should be the same as the angles between the bonds, and the distances between the centers of the spheres should be proportional to the distances between the corresponding atomic nuclei. The chemical element of each atom is often indicated by the sphere's color. In a ball-and-stick model, the radius of the spheres is usually much smaller than the rod lengths, in order to provide a clearer view of the atoms and bonds throughout the model. As a consequence, the model does not provide a clear insight about th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hofmann–Martius Rearrangement
The Hofmann–Martius rearrangement in organic chemistry is a rearrangement reaction converting an N-alkylated aniline to the corresponding aromatic ortho substituent, ortho and / or aromatic para substituent, para arene compound, aryl-alkylated aniline. The reaction requires heat, and the catalyst is an acid like hydrochloric acid. : When the catalyst is a metal halide the reaction is also called the Reilly–Hickinbottom rearrangement. The reaction is also known to work for aryl ethers and two conceptually related reactions are the Fries rearrangement and the Fischer–Hepp rearrangement. Its reaction mechanism centers around dissociation of the reactant with the positively charged organic residue R attacking the aniline ring in a Friedel–Crafts alkylation. In one study this rearrangement was applied to a 3-N(CH3)(C6H5)-2-oxindole:heating 1 in toluene at 80 °C gives 30% 2-o (ortho) and 37% 2-p (para) : The reaction is named after German chemists August Wilhelm von Hofmann ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hofmann–Löffler Reaction
The Hofmann–Löffler reaction (also referred to as Hofmann–Löffler–Freytag reaction, Löffler–Freytag reaction, Löffler–Hofmann reaction, as well as Löffler's method) is an organic reaction in which a cyclic amine 2 (pyrrolidine or, in some cases, piperidine) is generated by thermal or photochemical decomposition of ''N''-halogenated amine 1 in the presence of a strong acid (concentrated sulfuric acid or concentrated CF3CO2H). The Hofmann–Löffler–Freytag reaction proceeds via an intramolecular hydrogen atom transfer to a nitrogen-centered radical and is an example of a remote intramolecular free radical C–H functionalization. Historical perspective In 1878, the structure of piperidine was still unknown, and A. W. Hofmann made attempts to add hydrogen chloride or bromine to it in the belief that the compound possessed unsaturation (i.e. he performed standard alkene classification test reactions). In the course of his studies, A.W. Hofmann synthesized a number ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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