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Walter Hieber
Walter Hieber (18 December 1895 – 29 November 1976) was an inorganic chemist, known as the father of metal carbonyl chemistry. He was born 18 December 1895 and died 29 November 1976. Hieber's father was Johannes Hieber, an influential evangelical minister and politician. Hieber was educated at Tübingen, Würzburg, and Heidelberg. In 1935 he was appointed Director of the Inorganic Chemical Institute at the Technical University in Münich. Among his numerous research findings, Hieber prepared the first metal carbonyl hydrides such as H2Fe(CO)4 and HMn(CO)5. He discovered that metal carbonyls undergo nucleophilic attack by hydroxide, the “Hieber base reaction.” He and his students discovered several metal carbonyl compounds such as Re2(CO)10 and Os3(CO)12 He pioneered the development of metal carbonyl sulfides.Hieber, W. and Scharfenberg, C., "Einwirkung organischer Schwefelverbindungen auf die Carbonyls des Eisens", Chemische Berichte, 1940, volume 73, pages 10 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Technical University Munich
The Technical University of Munich (TUM or TU Munich; ) is a Public university, public research university in Munich, Bavaria, Germany. It specializes in engineering, technology, medicine, and applied science, applied and natural sciences. Established in 1868 by King Ludwig II of Bavaria, the university now has additional campuses in Garching, Freising, Heilbronn, Straubing, and Singapore, with the Campus Garching, Garching campus being its largest. The university is organized into seven schools, and is supported by numerous research centers. It is one of the largest universities in Germany, with 52,931 students and an annual budget of €1,892.9 million including the Rechts der Isar Hospital, university hospital. A ''University of Excellence'' under the German Universities Excellence Initiative, TUM is among the leading universities in the European Union. Its researchers and alumni include 18 Nobel Prize, Nobel laureates and 24 Leibniz Prize winners. History 19th century ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nucleophilic
In chemistry, a nucleophile is a chemical species that forms bonds by donating an electron pair. All molecules and ions with a free pair of electrons or at least one pi bond can act as nucleophiles. Because nucleophiles donate electrons, they are Lewis bases. ''Nucleophilic'' describes the affinity of a nucleophile to bond with positively charged atomic nuclei. Nucleophilicity, sometimes referred to as nucleophile strength, refers to a substance's nucleophilic character and is often used to compare the affinity of atoms. Neutral nucleophilic reactions with solvents such as alcohols and water are named solvolysis. Nucleophiles may take part in nucleophilic substitution, whereby a nucleophile becomes attracted to a full or partial positive charge, and nucleophilic addition. Nucleophilicity is closely related to basicity. The difference between the two is, that basicity is a thermodynamic property (i.e. relates to an equilibrium state), but nucleophilicity is a kinetic property ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Academic Staff Of The Technical University Of Munich
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 sessions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1976 Deaths
Events January * January 2 – The International Covenant on Economic, Social and Cultural Rights enters into force. * January 5 – The Pol Pot regime proclaims a new constitution for Democratic Kampuchea. * January 18 – Full diplomatic relations are established between Bangladesh and Pakistan 5 years after the Bangladesh Liberation War. * January 27 ** The United States vetoes a United Nations resolution that calls for an independent Palestinian state. ** The First Battle of Amgala breaks out between Morocco and Algeria in the Spanish Sahara. February * February 4 ** The 1976 Winter Olympics begin in Innsbruck, Austria. ** The 7.5 Guatemala earthquake affects Guatemala and Honduras with a maximum Mercalli intensity of IX (''Violent''), leaving 23,000 dead and 76,000 injured. * February 9 – The Australian Defence Force is formed by unification of the Australian Army, the Royal Australian Navy and the Royal Australian Air Force. * February 13 – General ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1895 Births
Events January * January 5 – Dreyfus affair: French officer Alfred Dreyfus is stripped of his army rank and sentenced to life imprisonment on Devil's Island (off French Guiana) on what is much later admitted to be a false charge of treason. * January 6 – The Wilcox rebellion, an attempt led by Robert Wilcox to overthrow the Republic of Hawaii and restore the Kingdom of Hawaii, begins with royalist troops landing at Waikiki Beach in O'ahu and clashing with republican defenders. The rebellion ends after three days and the remaining 190 royalists are taken prisoners of war. * January 12 – Britain's National Trust for Places of Historic Interest or Natural Beauty is founded by Octavia Hill, Robert Hunter and Canon Hardwicke Rawnsley. * January 13 – First Italo-Ethiopian War: Battle of Coatit – Italian forces defeat the Ethiopians. * January 15 – A warehouse fire and dynamite explosion kills 57 people, including 13 firefighters in Butt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Stuart Anderson
John Stuart Anderson FRS, FAA, (9 January 1908 – 25 December 1990) was a British and Australian scientist who was Professor of Chemistry at the University of Melbourne and Professor of Inorganic Chemistry at the University of Oxford.Hyde and P Day (1992): "John Stuart Anderson". ''Historical Records of Australian Science,'' Volume 9 Number 2 pp. 127–149. Published online as ''Biographical Memoirs of Deceased Fellows, Australian Academy of Science'': "John Stuart Anderson 1908–1990". Accessed 1 November 2007. He was born in , , the son ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alfred Stock
Alfred Stock (July 16, 1876 – August 12, 1946) was a German inorganic chemist. He did pioneering research on the hydrides of boron and silicon, coordination chemistry, mercury, and mercury poisoning. The German Chemical Society's Alfred-Stock Memorial Prize is named after him. Life Stock was born in Danzig (Gdańsk) and educated at the Friedrich-Werder grammar school in Berlin. In 1894 he began studies in chemistry at the Friedrich Wilhelm-University in Berlin. After finishing his dissertation about the quantitative separation of arsenic and antimony in the works of Emil Fischer he got his doctoral degree. In 1899 he worked with the French chemist and toxicologist Henri Moissan in Paris for one year. He was given the task of synthesizing still unknown compounds of boron and silicon. Five years later he became professor at the University of Breslau. In 1916 he succeeded Richard Willstätter as director at the Kaiser Wilhelm Institute for Chemistry in Berlin. After a sever ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cis Effect
In inorganic chemistry, the cis effect is defined as the labilization (or destabilization) of CO ligands that are ''cis'' to other ligands. CO is a well-known strong pi-accepting ligand in organometallic chemistry that will labilize in the ''cis'' position when adjacent to ligands due to steric and electronic effects. The system most often studied for the ''cis'' effect is an octahedral complex where X is the ligand that will labilize a CO ligand ''cis'' to it. Unlike the ''trans'' effect, which is most often observed in 4-coordinate square planar complexes, the ''cis'' effect is observed in 6-coordinate octahedral transition metal complexes. It has been determined that ligands that are weak sigma donors and non-pi acceptors seem to have the strongest ''cis''-labilizing effects. Therefore, the ''cis'' effect has the opposite trend of the ''trans''-effect, which effectively labilizes ligands that are ''trans'' to strong pi accepting and sigma donating ligands. Electron coun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triosmium Dodecacarbonyl
Triosmium dodecacarbonyl is a chemical compound with the formula Os3(CO)12. This yellow-colored metal carbonyl cluster is an important precursor to organo-osmium compounds. Many of the advances in cluster chemistry have arisen from studies on derivatives of Os3(CO)12 and its lighter analogue Ru3(CO)12. Structure and synthesis The cluster has D3h symmetry, consisting of an equilateral triangle of Os atoms, each of which bears two axial and two equatorial CO ligands. Each of the three osmium centers has an octahederal structure with four CO ligands and the other two osmium atoms. The Os–Os bond distance is 2.88 Å (288 pm). Ru3(CO)12 has the same structure, whereas Fe3(CO)12 is different, with two bridging CO ligands resulting in C2v symmetry. In solution, is fluxional as indicated by 13C NMR measurements. The barrier is estimated at 70 kJ/mol Os3(CO)12 is prepared by the direct reaction of OsO4 with carbon monoxide at 175 °C under high pressures: : 3 OsO4 + ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dirhenium Decacarbonyl
Dirhenium decacarbonyl is the inorganic compound with the chemical formula Re2(CO)10 . Commercially available, it is used as a starting point for the synthesis of many rhenium carbonyl complexes. It was first reported in 1941 by Walter Hieber, who prepared it by reductive carbonylation of rhenium. The compound consists of a pair of square pyramidal Re(CO)5 units joined via a Re-Re bond, which produces a homoleptic carbonyl complex. History In the 1930s Robert Mond developed methods which used increased pressure and temperature to produce various forms of metal carbonyl . A prominent scientist of the twentieth century, Walter Hieber was crucial to the further development of specifically the dirhenium decacarbonyl. Initial efforts produced mononuclear metal complexes, but upon further evaluation, Hieber discovered that by using Re2O7 as a starting material with no solvent, a dirhenium complex could be achieved producing a Re-Re interaction. Structure and properties The crystal s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydroxide
Hydroxide is a diatomic anion with chemical formula OH−. It consists of an oxygen and hydrogen atom held together by a single covalent bond, and carries a negative electric charge. It is an important but usually minor constituent of water. It functions as a base, a ligand, a nucleophile, and a catalyst. The hydroxide ion forms salts, some of which dissociate in aqueous solution, liberating solvated hydroxide ions. Sodium hydroxide is a multi-million-ton per annum commodity chemical. The corresponding electrically neutral compound HO• is the hydroxyl radical. The corresponding covalently bound group of atoms is the hydroxy group. Both the hydroxide ion and hydroxy group are nucleophiles and can act as catalysts in organic chemistry. Many inorganic substances which bear the word ''hydroxide'' in their names are not ionic compounds of the hydroxide ion, but covalent compounds which contain hydroxy groups. Hydroxide ion The hydroxide ion is naturally produced ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydride
In chemistry, a hydride is formally the anion of hydrogen (H−), a hydrogen ion with two electrons. In modern usage, this is typically only used for ionic bonds, but it is sometimes (and has been more frequently in the past) applied to all chemical compound, compounds containing covalent bond, covalently bound H atoms. In this broad and potentially archaic sense, water (H2O) is a hydride of oxygen, ammonia is a hydride of nitrogen, etc. In covalent compounds, it implies hydrogen is attached to a less electronegative chemical element, 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 of hydrogen, binary compounds with hydrogen, the exceptions being helium, He, neon, Ne, argon, Ar, krypton, Kr, promethium, Pm, osmium, Os, iridium, Ir, radon, Rn, francium, Fr, and radium, Ra. exotic atom#exotic molecules, Exotic molecules ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
