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Walter Rüdorff
Walter Rüdorff (October 3, 1909 – April 1, 1989) was a German chemist known for his research on clathrates of graphite and ternary oxides. Education and career Rüdorff was born in Berlin in 1909. He studied chemistry as an undergraduate at ''Technische Hochschule Berlin'' (now Technische Universität Berlin) and graduated in 1925. His graduate study was carried out under the supervision of Ulrich Hofmann at the same university, where he graduated with a PhD thesis titled ''Über die Kristallstruktur der Hexacarbonyle von Chrom, Molybdän und Wolfram''. He then moved to the University of Rostock along with Ulrich Hofmann and achieved his ''habilitation'' status with the thesis titled ''Neuartige Verbindungen mit Graphit'' in 1941. In 1942, Rüdorff moved to TU Wien following Ulrich Hofmann. He later took up a faculty position at University of Tübingen in 1947. He stayed in Tübingen until his retirement. Along with his supervisor Ulrich Hofmann and his father Karl Andreas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clathrates
A clathrate is a chemical substance consisting of a lattice that traps or contains molecules. The word ''clathrate'' is derived from the Latin (), meaning 'with bars, latticed'. Most clathrate compounds are polymeric and completely envelop the guest molecule, but in modern usage clathrates also include host–guest complexes and inclusion compounds.Atwood, J. L. (2012) "Inclusion Compounds" in ''Ullmann's Encyclopedia of Industrial Chemistry''. Wiley-VCH, Weinheim. According to IUPAC, clathrates are inclusion compounds "in which the guest molecule is in a cage formed by the host molecule or by a lattice of host molecules." The term refers to many molecular hosts, including calixarenes and cyclodextrins and even some inorganic polymers such as zeolites. Clathrates can be divided into two categories: clathrate hydrates and inorganic clathrates. Each clathrate is made up of a framework and guests that reside the framework. Most common clathrate crystal structures can be composed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inorganic Chemists
An inorganic compound is typically a chemical compound that lacks carbon–hydrogen bondsthat is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as ''inorganic chemistry''. Inorganic compounds comprise most of the Earth's crust, although the compositions of the deep mantle remain active areas of investigation. All allotropes (structurally different pure forms of an element) and some simple carbon compounds are often considered inorganic. Examples include the allotropes of carbon (graphite, diamond, buckminsterfullerene, graphene, etc.), carbon monoxide , carbon dioxide , carbides, and salts of inorganic anions such as carbonates, cyanides, cyanates, thiocyanates, isothiocyanates, etc. Many of these are normal parts of mostly organic systems, including organisms; describing a chemical as inorganic does not necessarily mean that it cannot occur within living things. History Friedrich Wöhler's conversion of am ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
German Chemists
German(s) may refer to: * Germany, the country of the Germans and German things **Germania (Roman era) * Germans, citizens of Germany, people of German ancestry, or native speakers of the German language ** For citizenship in Germany, see also German nationality law **Germanic peoples (Roman era) *German diaspora * German language * German cuisine, traditional foods of Germany People * German (given name) * German (surname) * Germán, a Spanish name Places * German (parish), Isle of Man * German, Albania, or Gërmej * German, Bulgaria * German, Iran * German, North Macedonia * German, New York, U.S. * Agios Germanos, Greece Other uses * German (mythology), a South Slavic mythological being * Germans (band), a Canadian rock band * "German" (song), a 2019 song by No Money Enterprise * ''The German'', a 2008 short film * "The Germans", an episode of ''Fawlty Towers'' * ''The German'', a nickname for Congolese rebel André Kisase Ngandu See also * Germanic (disambiguat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1989 Deaths
1989 was a turning point in political history with the " Revolutions of 1989" which ended communism in Eastern Bloc of Europe, starting in Poland and Hungary, with experiments in power-sharing coming to a head with the opening of the Berlin Wall in November, the Velvet Revolution in Czechoslovakia and the overthrow of the communist dictatorship in Romania in December; the movement ended in December 1991 with the dissolution of the Soviet Union. Revolutions against communist governments in Eastern Europe mainly succeeded, but the year also saw the suppression by the Chinese government of the 1989 Tiananmen Square protests in Beijing. It was the year of the first Brazilian direct presidential election in 29 years, since the end of the military government in 1985 that ruled the country for more than twenty years, and marked the redemocratization process's final point. F. W. de Klerk was elected as State President of South Africa, and his regime gradually dismantled th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1909 Births
Events January–February * January 4 – Explorer Aeneas Mackintosh of the Imperial Trans-Antarctic Expedition escapes death by fleeing across drift ice, ice floes. * January 7 – Colombia recognizes the independence of Panama. * January 9 – The British Nimrod Expedition, ''Nimrod'' Expedition to the South Pole, led by Ernest Shackleton, arrives at the Farthest South, farthest south reached by any prior expedition, at 88°23' S, prior to turning back due to diminishing supplies. * January 11 – The International Joint Commission on US-Canada boundary waters is established. * January 16 – Members of the ''Nimrod'' Expedition claim to have found the magnetic South Pole (but the location recorded may be incorrect). * January 24 – The White Star Liner RMS Republic (1903), RMS ''Republic'' sinks the day after a collision with ''SS Florida'' off Nantucket. Almost all of the 1,500 passengers are rescued. * January 28 – The last United States t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Academic Staff Of The University Of Tübingen
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 skill, north of 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 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, hence the expression "the groves of Academe". In these gardens, the philosopher Plato conversed with followers. Plato developed his sessio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cathode
A cathode is the electrode from which a conventional current leaves a polarized electrical device such as a lead-acid battery. This definition can be recalled by using the mnemonic ''CCD'' for ''Cathode Current Departs''. Conventional current describes the direction in which positive charges move. Electrons, which are the carriers of current in most electrical systems, have a negative electrical charge, so the movement of electrons is ''opposite'' to that of the conventional current flow: this means that electrons flow ''into'' the device's cathode from the external circuit. For example, the end of a household battery marked with a + (plus) is the cathode. The electrode through which conventional current flows the other way, into the device, is termed an anode. Charge flow Conventional current flows from cathode to anode outside the cell or device (with electrons moving in the opposite direction), regardless of the cell or device type and operating mode. Cathode polarity ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chalcogenide
: 220px, Cadmium sulfide, a prototypical metal chalcogenide, is used as a yellow pigment. A chalcogenide is a chemical compound consisting of at least one chalcogen anion and at least one more electropositive element. Although all group 16 elements of the periodic table are defined as chalcogens, the term chalcogenide is more commonly reserved for sulfides, selenides, tellurides, and polonides, rather than oxides. Many metal ores exist as chalcogenides. Photoconductive chalcogenide glasses are used in xerography. Some pigments and catalysts are also based on chalcogenides. The metal dichalcogenide MoS2 is a common solid lubricant. Alkali metal and alkaline earth chalcogenides Alkali metal and alkaline earth monochalcogenides are salt-like, being colourless and often water-soluble. The sulfides tend to undergo hydrolysis to form derivatives containing bisulfide (SH−) anions. The alkali metal chalcogenides often crystallize with the antifluorite structure and the alkal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Titanium Disulfide
Titanium disulfide is an inorganic compound with the formula Ti S2. A golden yellow solid with high electrical conductivity, it belongs to a group of compounds called transition metal di chalcogenides, which consist of the stoichiometry M E2. TiS2 has been employed as a cathode material in rechargeable batteries. Structure With a layered structure, TiS2 adopts a hexagonal close packed (hcp) structure, analogous to cadmium iodide (CdI2). In this motif, half of the octahedral holes are filled with a "cation", in this case Ti4+. Each Ti centre is surrounded by six sulfide ligands in an octahedral structure. Each sulfide is connected to three Ti centres, the geometry at S being pyramidal. Several metal di chalcogenides adopt similar structures, but some, notably MoS2, do not. The layers of TiS2 consist of covalent Ti-S bonds. The individual layers of TiS2 are bound together by van der Waals forces, which are relatively weak intermolecular forces. It crystallises in the space ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
