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Hans-Werner Wanzlick
Hans-Werner Wanzlick (1917-1988) was a German chemist. A Professor of chemistry at Technische Universität Berlin he is notable for work on persistent carbenes and for proposing the Wanzlick equilibrium between saturated imidazolin-2-ylidenes and their dimers — which he called "''das doppelte Lottchen''", after a 1949 novel by Erich Kästner about a pair of mischievous twins. Anthony J. Arduengo, III (1999) ''Looking for Stable Carbenes: The Difficulty in Starting Anew''. Accounts of Chemical Research, volume 32, number 11, pages 913–921. References * Hans-Werner Wanzlick (1958), letter to Linus Pauling Linus Carl Pauling ( ; February 28, 1901August 19, 1994) was an American chemist and peace activist. He published more than 1,200 papers and books, of which about 850 dealt with scientific topics. ''New Scientist'' called him one of the 20 gre ... (in German). Linus Pauling's Correspondence, item #444.6. Academic staff of Technische Universität B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Berlin
Berlin ( ; ) is the Capital of Germany, capital and largest city of Germany, by both area and List of cities in Germany by population, population. With 3.7 million inhabitants, it has the List of cities in the European Union by population within city limits, highest population within its city limits of any city in the European Union. The city is also one of the states of Germany, being the List of German states by area, third smallest state in the country by area. Berlin is surrounded by the state of Brandenburg, and Brandenburg's capital Potsdam is nearby. The urban area of Berlin has a population of over 4.6 million and is therefore the most populous urban area in Germany. The Berlin/Brandenburg Metropolitan Region, Berlin-Brandenburg capital region has around 6.2 million inhabitants and is Germany's second-largest metropolitan region after the Rhine-Ruhr region, as well as the List of EU metropolitan areas by GDP, fifth-biggest metropolitan region by GDP in the European Union. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Angewandte Chemie
''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] |
1917 Births
Events Below, the events of World War I have the "WWI" prefix. January * January 9 – WWI – Battle of Rafa: The last substantial Ottoman Army garrison on the Sinai Peninsula is captured by the Egyptian Expeditionary Force's Desert Column. * January 10 – Imperial Trans-Antarctic Expedition: Seven survivors of the Ross Sea party are rescued after being stranded for several months. * January 11 – Unknown saboteurs set off the Kingsland Explosion at Kingsland (modern-day Lyndhurst, New Jersey), one of the events leading to United States involvement in WWI. * January 16 – The Danish West Indies is sold to the United States for $25 million (equivalent to $ million in ). * January 22 – WWI: United States President Woodrow Wilson calls for "peace without victory" in Germany. * January 25 – WWI: British armed merchantman is sunk by mines off Lough Swilly (Ireland), with the loss of 354 of the 475 aboard. * January 26 – The se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Academic Staff Of Technische Universität Berlin
An academy (Attic Greek: Ἀκαδήμεια; Koine Greek Ἀκαδημία) is an institution of tertiary education. The name traces back to Plato's school of philosophy, founded approximately 386 BC at Akademia, a sanctuary of Athena, the goddess of wisdom and Skills, skill, north of Ancient Athens, Athens, Greece. The Royal Spanish Academy defines academy as scientific, literary or artistic society established with public authority and as a teaching establishment, public or private, of a professional, artistic, technical or simply practical nature. Etymology The word comes from the ''Academy'' in ancient Greece, which derives from the Athenian hero, ''Akademos''. Outside the city walls of Athens, the Gymnasium (ancient Greece), gymnasium was made famous by Plato as a center of learning. The sacred space, dedicated to the goddess of wisdom, Athena, had formerly been an olive Grove (nature), grove, hence the expression "the groves of Academe". In these gardens, the philos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linus Pauling
Linus Carl Pauling ( ; February 28, 1901August 19, 1994) was an American chemist and peace activist. He published more than 1,200 papers and books, of which about 850 dealt with scientific topics. ''New Scientist'' called him one of the 20 greatest scientists of all time. For his scientific work, Pauling was awarded the Nobel Prize in Chemistry in 1954. For his peace activism, he was awarded the Nobel Peace Prize in 1962. He is one of five people to have Nobel Prize#Multiple laureates, won more than one Nobel Prize. Of these, he is the only person to have been awarded two unshared Nobel Prizes, and one of two people to be awarded Nobel Prizes in different fields, the other being Marie Curie. Pauling was one of the founders of the fields of quantum chemistry and molecular biology. His contributions to the theory of the chemical bond include the concept of orbital hybridisation and the first accurate scale of electronegativity, electronegativities of the elements. Pauling also wo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Erich Kästner
Emil Erich Kästner (; 23 February 1899 – 29 July 1974) was a German writer, poet, screenwriter and satirist, known primarily for his humorous, socially astute poems and for children's books including ''Emil and the Detectives'' and '' Lisa and Lottie''. He received the international Hans Christian Andersen Award in 1960 for his autobiography '. He was nominated for the Nobel Prize in Literature in six separate years. Biography Dresden (1899–1919) Kästner was born in Dresden, Saxony, and grew up on Königsbrücker Straße in Dresden's Äußere Neustadt. Close by, the Erich Kästner Museum was subsequently opened in the Villa Augustin that had belonged to Kästner's uncle Franz Augustin. Kästner's father, Emil Richard Kästner, was a master saddlemaker. His mother, Ida Amalia (née Augustin), had been a maidservant, but in her thirties she trained as a hairstylist in order to supplement her husband's income. Kästner had a particularly close relationship with his mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lottie And Lisa
''Lisa and Lottie'', published in the United Kingdom and Australia as ''The Parent Trap'', (original German title: ''Das doppelte Lottchen'', "The Double Lottie") is a 1949 German children's novel by Erich Kästner. The book is about identical twin girls whose parents separated them in infancy upon divorcing, only to reunite at a summer camp years later before switching places. The book originates from a film scenario Kästner developed during World War II that was never produced. In 1942, when he was briefly allowed by the Nazi authorities to work as a screenwriter, he proposed the plot to Josef von Báky, under the title ''The Great Secret'', but the Nazis once again forbade him to work. After the war, Kästner wrote his idea into the book ''Das doppelte Lottchen'', which was illustrated by Walter Trier. A successful novel, ''Das doppelte Lottchen'' has been adapted for the screen multiple times, most notably Disney's 1961 American film ''The Parent Trap (1961 film), Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemische Berichte
''Chemische Berichte'' (usually abbreviated as ''Ber.'' or ''Chem. Ber.'') was a German-language scientific journal of all disciplines of chemistry founded in 1868. It was one of the oldest scientific journals in chemistry, until it merged with '' Recueil des Travaux Chimiques des Pays-Bas'' to form ''Chemische Berichte/Recueil'' in 1997. ''Chemische Berichte/Recueil'' was then merged with other European journals in 1998 to form ''European Journal of Inorganic Chemistry''. History Founded in 1868 as ''Berichte der Deutschen Chemischen Gesellschaft'' (, CODEN BDCGAS), it operated under this title until 1928 (Vol. 61). The journal was then split into: * ''Berichte der Deutschen Chemischen Gesellschaft, A: Vereins-Nachrichten'' (, CODEN BDCAAS), and * ''Berichte der Deutschen Chemischen Gesellschaft, B: Abhandlungen'' (, CODEN BDCBAD). Vol. 78 and 79 (1945–1946) were omitted and not published due to World War II. The journal was renamed ''Chemische Berichte'' (, CODEN CHBEAM) in 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dimer (chemistry)
In chemistry, dimerization is the process of joining two identical or similar Molecular entity, molecular entities by Chemical bond, bonds. The resulting bonds can be either strong or weak. Many symmetrical chemical species are described as dimers, even when the monomer is unknown or highly unstable. The term ''homodimer'' is used when the two subunits are identical (e.g. A–A) and ''heterodimer'' when they are not (e.g. A–B). The reverse of dimerization is often called Dissociation (chemistry), dissociation. When two oppositely-charged ions associate into dimers, they are referred to as ''Bjerrum pairs'', after Danish chemist Niels Bjerrum. Noncovalent dimers Anhydrous carboxylic acids form dimers by hydrogen bonding of the acidic hydrogen and the carbonyl oxygen. For example, acetic acid forms a dimer in the gas phase, where the monomer units are held together by hydrogen bonds. Many OH-containing molecules form dimers, e.g. the water dimer. Dimers that form based on w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Germany
Germany, officially the Federal Republic of Germany, is a country in Central Europe. It lies between the Baltic Sea and the North Sea to the north and the Alps to the south. Its sixteen States of Germany, constituent states have a total population of over 84 million in an area of , making it the most populous member state of the European Union. It borders Denmark to the north, Poland and the Czech Republic to the east, Austria and Switzerland to the south, and France, Luxembourg, Belgium, and the Netherlands to the west. The Capital of Germany, nation's capital and List of cities in Germany by population, most populous city is Berlin and its main financial centre is Frankfurt; the largest urban area is the Ruhr. Settlement in the territory of modern Germany began in the Lower Paleolithic, with various tribes inhabiting it from the Neolithic onward, chiefly the Celts. Various Germanic peoples, Germanic tribes have inhabited the northern parts of modern Germany since classical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dihydroimidazol-2-ylidene
Dihydroimidazol-2-ylidene is a hypothetical organic compound with formula C3H6N2. It would be a heterocyclic compound, formally derived from imidazolidine with two hydrogen atoms removed from carbon number 2, leaving two vacant chemical bonds — which makes it a carbene. Although carbenes in general are extremely short-lived, some derivatives of this compound are surprisingly stable, and form an important class of the persistent carbenes. They include the first stable carbenes postulated (but not isolated) by Hans-Werner Wanzlick around 1960. They also include an example of the (saturated) imidazolin-2-ylidene (carbene) reported by Anthony Joseph Arduengo, III, A.J. Arduengo in 1995. References Carbenes Imidazolines Hypothetical chemical compounds {{heterocyclic-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wanzlick Equilibrium
The Wanzlick equilibrium is a chemical equilibrium between a relatively stable carbene compound and its dimer. The equilibrium was proposed to apply to certain electron-rich alkenes, such as tetraminoethylenes, which have been called "carbene dimers." Such equilibria occur, but the mechanism does not proceed simply, but requires catalysts. Original conjecture In 1960, Hans-Werner Wanzlick and E. Schikora proposed that carbenes derived from dihydroimidazol-2-ylidene were generated by vacuum pyrolysis of 2-trichloromethyl dihydroimidazole derivatives, with the loss of chloroform. Wanzlick and Schikora believed that once prepared these carbenes existed in an unfavourable equilibrium with their corresponding dimers. This assertion was based on reactivity studies which they believed showed that the free carbene reacted with electrophiles (E-X). The dimer (a substituted tetraaminoethylene) was believed to be inactive to the electrophiles (E-X), and thought to merely act as a stable ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
