|
σ-bishomoaromaticity
Horst Prinzbach (20 July 1931 in Haslach im Kinzigtal – 18 September 2012 in Freiburg im Breisgau) was a German chemist and professor emeritus. Prinzbach studied chemistry at the University of Freiburg and received his PhD under Arthur Lüttringhaus. He joined William von Eggers Doering at Yale University for postdoctoral work. In 1962 he completed his habilitation at Freiburg with a dissertation on sesquifulvalenes. In 1965 he became a professor of organic chemistry at the University of Lausanne, Switzerland, and in 1969 he became a full professor in organic chemistry at Freiburg. Main research activities Of his many research interests in organic chemistry, including photochemistry with unusual chromophores, synthesis of new carba-/hetera cages, radical cations, dications, total synthesis of aminoglycosid antibiotics, and enzymes, Prinzbach was probably best known for the pagodane route towards dodecahedrane. In the course of his research, the phenomenon of σ-bisho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pagodane
Pagodane is an organic compound with formula whose carbon skeleton was said to resemble a pagoda, hence the name. It is a polycyclic hydrocarbon whose molecule has the ''D''2''h'' point symmetry group. The compound is a highly crystalline solid that melts at 243 °C, is barely soluble in most organic solvents and moderately soluble in benzene and chloroform. It sublimes at low pressure. The name pagodane is used more generally for any member of a family of compounds whose molecular skeletons have the same 16-carbon central cage as the basic compound. Each member can be seen as the result of connecting eight atoms of this cage in pairs by four alkane chains. The general member is denoted 'm''.''n''.''p''.''q''agodane where ''m'', ''n'', ''p'' and ''q'' are the number of carbons of those four chains. The general formula is then where ''s''= ''m''+''n''+''p''+''q''. In particular, the basic compound has those carbons connected by four methylene bridges (''m''=''n''=''p''=''q ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
σ-bishomoaromaticity
Horst Prinzbach (20 July 1931 in Haslach im Kinzigtal – 18 September 2012 in Freiburg im Breisgau) was a German chemist and professor emeritus. Prinzbach studied chemistry at the University of Freiburg and received his PhD under Arthur Lüttringhaus. He joined William von Eggers Doering at Yale University for postdoctoral work. In 1962 he completed his habilitation at Freiburg with a dissertation on sesquifulvalenes. In 1965 he became a professor of organic chemistry at the University of Lausanne, Switzerland, and in 1969 he became a full professor in organic chemistry at Freiburg. Main research activities Of his many research interests in organic chemistry, including photochemistry with unusual chromophores, synthesis of new carba-/hetera cages, radical cations, dications, total synthesis of aminoglycosid antibiotics, and enzymes, Prinzbach was probably best known for the pagodane route towards dodecahedrane. In the course of his research, the phenomenon of σ-bisho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dodecahedrane
Dodecahedrane is a chemical compound, a hydrocarbon with formula , whose carbon atoms are arranged as the vertices (corners) of a regular dodecahedron. Each carbon is bound to three neighbouring carbon atoms and to a hydrogen atom. This compound is one of the three possible Platonic hydrocarbons, the other two being cubane and tetrahedrane. Dodecahedrane does not occur in nature and has no significant uses. It was synthesized by Leo Paquette in 1982, primarily for the "aesthetically pleasing symmetry of the dodecahedral framework". For many years, dodecahedrane was the simplest real carbon-based molecule with full icosahedral symmetry. Buckminsterfullerene (), discovered in 1985, also has the same symmetry, but has three times as many carbons and 50% more atoms overall. The synthesis of the C20 fullerene in 2000, from brominated dodecahedrane, may have demoted to second place. Structure The angle between the C-C bonds in each carbon atom is 108°, which is the angle between a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pagodane
Pagodane is an organic compound with formula whose carbon skeleton was said to resemble a pagoda, hence the name. It is a polycyclic hydrocarbon whose molecule has the ''D''2''h'' point symmetry group. The compound is a highly crystalline solid that melts at 243 °C, is barely soluble in most organic solvents and moderately soluble in benzene and chloroform. It sublimes at low pressure. The name pagodane is used more generally for any member of a family of compounds whose molecular skeletons have the same 16-carbon central cage as the basic compound. Each member can be seen as the result of connecting eight atoms of this cage in pairs by four alkane chains. The general member is denoted 'm''.''n''.''p''.''q''agodane where ''m'', ''n'', ''p'' and ''q'' are the number of carbons of those four chains. The general formula is then where ''s''= ''m''+''n''+''p''+''q''. In particular, the basic compound has those carbons connected by four methylene bridges (''m''=''n''=''p''=''q ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dodecahedrane
Dodecahedrane is a chemical compound, a hydrocarbon with formula , whose carbon atoms are arranged as the vertices (corners) of a regular dodecahedron. Each carbon is bound to three neighbouring carbon atoms and to a hydrogen atom. This compound is one of the three possible Platonic hydrocarbons, the other two being cubane and tetrahedrane. Dodecahedrane does not occur in nature and has no significant uses. It was synthesized by Leo Paquette in 1982, primarily for the "aesthetically pleasing symmetry of the dodecahedral framework". For many years, dodecahedrane was the simplest real carbon-based molecule with full icosahedral symmetry. Buckminsterfullerene (), discovered in 1985, also has the same symmetry, but has three times as many carbons and 50% more atoms overall. The synthesis of the C20 fullerene in 2000, from brominated dodecahedrane, may have demoted to second place. Structure The angle between the C-C bonds in each carbon atom is 108°, which is the angle between a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
People From The Republic Of Baden
A person ( : people) is a being that has certain capacities or attributes such as reason, morality, consciousness or self-consciousness, and being a part of a culturally established form of social relations such as kinship, ownership of property, or legal responsibility. The defining features of personhood and, consequently, what makes a person count as a person, differ widely among cultures and contexts. In addition to the question of personhood, of what makes a being count as a person to begin with, there are further questions about personal identity and self: both about what makes any particular person that particular person instead of another, and about what makes a person at one time the same person as they were or will be at another time despite any intervening changes. The plural form "people" is often used to refer to an entire nation or ethnic group (as in "a people"), and this was the original meaning of the word; it subsequently acquired its use as a plural form of per ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
People From Haslach Im Kinzigtal
A person ( : people) is a being that has certain capacities or attributes such as reason, morality, consciousness or self-consciousness, and being a part of a culturally established form of social relations such as kinship, ownership of property, or legal responsibility. The defining features of personhood and, consequently, what makes a person count as a person, differ widely among cultures and contexts. In addition to the question of personhood, of what makes a being count as a person to begin with, there are further questions about personal identity and self: both about what makes any particular person that particular person instead of another, and about what makes a person at one time the same person as they were or will be at another time despite any intervening changes. The plural form "people" is often used to refer to an entire nation or ethnic group (as in "a people"), and this was the original meaning of the word; it subsequently acquired its use as a plural form of per ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2012 Deaths
This is a list of deaths of notable people, organised by year. New deaths articles are added to their respective month (e.g., Deaths in ) and then linked here. 2022 2021 2020 2019 2018 2017 2016 2015 2014 2013 2012 2011 2010 2009 2008 2007 2006 2005 2004 2003 2002 2001 2000 1999 1998 1997 1996 1995 1994 1993 1992 1991 1990 1989 1988 1987 See also * Lists of deaths by day The following pages, corresponding to the Gregorian calendar, list the historical events, births, deaths, and holidays and observances of the specified day of the year: Footnotes See also * Leap year * List of calendars * List of non-standard ... * Deaths by year {{DEFAULTSORT:deaths by year ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1931 Births
Events January * January 2 – South Dakota native Ernest Lawrence invents the cyclotron, used to accelerate particles to study nuclear physics. * January 4 – German pilot Elly Beinhorn begins her flight to Africa. * January 22 – Sir Isaac Isaacs is sworn in as the first Australian-born Governor-General of Australia. * January 25 – Mohandas Gandhi is again released from imprisonment in India. * January 27 – Pierre Laval forms a government in France. February * February 4 – Soviet leader Joseph Stalin gives a speech calling for rapid industrialization, arguing that only strong industrialized countries will win wars, while "weak" nations are "beaten". Stalin states: "We are fifty or a hundred years behind the advanced countries. We must make good this distance in ten years. Either we do it, or they will crush us." The first five-year plan in the Soviet Union is intensified, for the industrialization and collectivization of agriculture. * February 10 †... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gesellschaft Deutscher Chemiker
The German Chemical Society (German: ', GDCh) is a learned society and professional association founded in 1949 to represent the interests of German chemists in local, national and international contexts. GDCh "brings together people working in chemistry and the molecular sciences and supports their striving for positive, sustainable scientific advance – for the good of humankind and the environment, and a future worth living for."Gesellschaft Deutscher Chemiker (GDCh)About us, Mission Statement and History/ref> History The earliest precursor of today's GDCh was the German Chemical Society (', DChG). Adolf von Baeyer was prominent among the German chemists who established DChG in 1867; and August Wilhelm von Hofmann was the first president. This society was modeled after the British Chemical Society, which was the precursor of the Royal Society of Chemistry. Like its British counterpart, DChG sought to foster the communication of new ideas and facts throughout Germany and acros ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adolf Von Baeyer
Johann Friedrich Wilhelm Adolf von Baeyer (; 31 October 1835 – 20 August 1917) was a German chemist who synthesised indigo and developed a nomenclature for cyclic compounds (that was subsequently extended and adopted as part of the IUPAC organic nomenclature). He was ennobled in the Kingdom of Bavaria in 1885 and was the 1905 recipient of the Nobel Prize in Chemistry.''Adolf von Baeyer: Winner of the Nobel Prize for Chemistry 1905 '' Armin de Meijere Angewandte Chemie International Edition Volume 44, Issue 48, Pages 7836 – 7840 2005''Abstract/ref> Family and education Baeyer was born in Berlin as the son of the noted geodesist and captain of the Royal Prussian Army Johann Jacob Baeyer and his wife Eugenie Baeyer née Hitzig (1807–1843). Both his parents were Lutherans at the time of his birth and he was raised in the Lutheran religion. His mother was the daughter of Julius Eduard Hitzig and a member of the originally Jewish Itzig family, and had converted to Christianity ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aromaticity
In chemistry, aromaticity is a chemical property of cyclic ( ring-shaped), ''typically'' planar (flat) molecular structures with pi bonds in resonance (those containing delocalized electrons) that gives increased stability compared to saturated compounds having single bonds, and other geometric or connective non-cyclic arrangements with the same set of atoms. Aromatic rings are very stable and do not break apart easily. Organic compounds that are not aromatic are classified as aliphatic compounds—they might be cyclic, but only aromatic rings have enhanced stability. The term ''aromaticity'' with this meaning is historically related to the concept of having an aroma, but is a distinct property from that meaning. Since the most common aromatic compounds are derivatives of benzene (an aromatic hydrocarbon common in petroleum and its distillates), the word ''aromatic'' occasionally refers informally to benzene derivatives, and so it was first defined. Nevertheless, many non-be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
_1938.jpg "Click for more on -> People From The Republic Of Baden")
.png "Click for more on -> Aromaticity")