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Borylene
A borylene is the boron analogue of a carbene. The general structure is R-B: with R an organic residue and B a boron atom with two unshared electrons. Borylenes are of academic interest in organoboron chemistry. A singlet ground state is predominant with boron having two vacant sp2 orbitals and one doubly occupied one. With just one additional substituent the boron is more electron deficient than the carbon atom in a carbene. For this reason stable borylenes are more uncommon than stable carbenes. Some borylenes such as boron monofluoride (BF) and boron monohydride (BH) the parent compound also known simply as borylene, have been detected in microwave spectroscopy and may exist in stars. Other borylenes exist as reactive intermediates and can only be inferred by chemical trapping. The first stable terminal borylene complex OC)5WBN(SiMe3)2was reported by Holger Braunschweig et al. in 1998. In this compound a borylene is coordinated to a transition metal. Borylenes are also s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boron Monofluoride
Boron monofluoride or fluoroborylene is a chemical compound with formula BF, one atom of boron and one of fluorine. It was discovered as an unstable gas and only in 2009 found to be a stable ligand combining with transition metals, in the same way as carbon monoxide. It is a subhalide, containing fewer than the normal number of fluorine atoms, compared with boron trifluoride. It can also be called a borylene, as it contains boron with two unshared electrons. BF is isoelectronic with carbon monoxide and dinitrogen; each molecule has 14 electrons. Structure The experimental B–F bond length is 1.26267 Å. Despite being isoelectronic to the triple-bonded species CO and N2, computational studies generally agree that the true bond order is much lower than 3. One reported computed bond order for the molecule is 1.4, compared with 2.6 for CO and 3.0 for N2. BF is unusual in that the dipole moment is inverted with fluorine having a positive charge even though it is the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holger Braunschweig
Holger Braunschweig is Head and Chair of Inorganic Chemistry at the Julius-Maximilians-University of Würzburg in Würzburg, Germany. He is best known for founding the field of transition metal- boron multiple bonding (transition metal borylenes), the synthesis of the first stable compounds containing boron-boron and boron-oxygen triple bonds, the isolation of the first non-carbon/nitrogen main-group dicarbonyl, and the first fixation of dinitrogen at an element of the p-block of the periodic table. By modifying a strategy pioneered by Prof. Gregory Robinson of the University of Georgia, Braunschweig also discovered the first rational and high-yield synthesis of neutral compounds containing boron-boron double bonds ( diborenes). In 2016 Braunschweig isolated the first compounds of beryllium in the oxidation state of zero. Education and research career Braunschweig obtained his Ph.D. and Habilitation from RWTH Aachen with P. Paetzold and worked as a postdoctoral researcher wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organoboron Chemistry
Organoborane or organoboron compounds are chemical compounds of boron and carbon that are organic derivatives of BH3, for example trialkyl boranes. Organoboron chemistry or organoborane chemistry is the chemistry of these compounds. Organoboron compounds are important reagents in organic chemistry enabling many chemical transformations, the most important one called hydroboration. Reactions of organoborates and boranes involve the transfer of a nucleophilic group attached to boron to an electrophilic center either inter- or intramolecularly. α,β-Unsaturated borates, as well as borates with a leaving group at the α position, are highly susceptible to intramolecular 1,2-migration of a group from boron to the electrophilic α position. Oxidation or protonolysis of the resulting organoboranes may generate a variety of organic products, including alcohols, carbonyl compounds, alkenes, and halides. Properties of the B-C bond The C-B bond has low polarity (the difference in electron ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boron Monohydride
Borane(1), boron monohydride, hydridoboron or borylene is the molecule with the formula BH. It exists as a gas but rapidly degrades when condensed. By contrast, the cluster B12H122- (dodecaborate), which has very similar empirical formula, forms robust salts. Formation Boron monohydride can be formed from borane carbonyl exposed to ultraviolet light. BH3CO → BH + CH2O Boron monohydride is formed when boron compounds are heated to a high temperature in the presence of hydrogen. Boron monohydride is formed when the boron anion B− reacts with a hydrogen ion H+. It is also formed when atomic boron reacts with hydrogen. B + H2 → BH + H. There is too much energy in the reaction for BH2 to be stable. Boron monohydride probably exists in sunspots, but as of 2008 has not been detected. Properties The ionization potential is around 9.77 eV. The dissociation energy for the ground state molecule is 81.5 kcal/mol. The electron affinity is roughly 0.3 eV, and the HB− ion ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Typical Borylene '', an American Comedy Central television series
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Typical may refer to: * ''Typical'' (album), Peter Hammill * "Typical" (song), song by MuteMath *"Typical", song by Frazier Chorus from ''Sue'', 1987 *''Typical'', story collection by Padgett Powell, 1991 See also *''Typical Rick ''Typical Rick'' is an American television series produced by Comedy Central, created by Nicholaus Goossen and Nick Swardson. Comedy Central declined to renew the series for a third season. Cast * Nick Swardson as Gary * Simon Rex as Rick * Mega ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HOMO Diborene
''Homo'' () is the genus that emerged in the (otherwise extinct) genus ''Australopithecus'' that encompasses the extant species ''Homo sapiens'' (modern humans), plus several extinct species classified as either ancestral to or closely related to modern humans (depending on the species), most notably ''Homo erectus'' and ''Homo neanderthalensis''. The genus emerged with the appearance of ''Homo habilis'' just over 2 million years ago. ''Homo'', together with the genus ''Paranthropus'', is probably sister to ''Australopithecus africanus'', which itself had previously split from the lineage of '' Pan'', the chimpanzees. ''Homo erectus'' appeared about 2 million years ago and, in several early migrations, spread throughout Africa (where it is dubbed ''Homo ergaster'') and Eurasia. It was likely that the first human species lived in a hunter-gatherer society and was able to control fire. An adaptive and successful species, ''Homo erectus'' persisted for more than a million years ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LUMO Diborene
In chemistry, HOMO and LUMO are types of molecular orbitals. The acronyms stand for ''highest occupied molecular orbital'' and ''lowest unoccupied molecular orbital'', respectively. HOMO and LUMO are sometimes collectively called the ''frontier orbitals'', such as in the frontier molecular orbital theory. Gap The energy difference between the HOMO and LUMO is ''the HOMO–LUMO gap''. Its size can be used to predict the strength and stability of transition metal complexes, as well as the colors they produce in solution.Griffith, J. S. and L. E. Orgel"Ligand Field Theory" ''Q. Rev. Chem. Soc.'' 1957, 11, 381–383. As a rule of thumb, the larger a compound's HOMO-LUMO gap, the more stable the compound. Semiconductors The HOMO level is to organic semiconductors roughly what the maximum valence band is to inorganic semiconductors and quantum dots. The same analogy can be made between the LUMO level and the conduction band minimum.Bredas, J,-L"Mind the gap!" ''Mater. Horiz.'' 201 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BB Sigma NBO
BB, Bb, or similar, may refer to: In arts and entertainment *BB, abbreviation for a catalogue of works by Béla Bartók * ''BB'' (album), by Mod Sun (2017) *"BB Talk", 2015 song by Miley Cyrus * BB (Transformers), a character in the franchise *BB, pseudonym of author and artist Denys Watkins-Pitchford * Les B.B., a Canadian band from Quebec *BattleBots, a robot combat TV show *Beast Boy, a comic book character *Beyond Birthday, a character from the novel '' Death Note Another Note: The Los Angeles BB Murder Cases'' * Big Brother (''Nineteen Eighty-Four'') or BB in Orwell's novel * ''Big Brother'' (TV series), home living reality TV popularity contest show *Billy Butcher, supporting character and final antagonist of the ''The Boys'' comic book series ** ''Butcher, Baker, Candlestickmaker'', spin-off comic miniseries of ''The Boys'', following Billy Butcher *** "Butcher, Baker, Candlestick Maker" (''The Boys''), television adaptation of the comic miniseries *BB, the productio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boron Dinitrogen Activation
Boron is a chemical element with the symbol B and atomic number 5. In its crystalline form it is a brittle, dark, lustrous metalloid; in its amorphous form it is a brown powder. As the lightest element of the ''boron group'' it has three valence electrons for forming covalent bonds, resulting in many compounds such as boric acid, the mineral sodium borate, and the ultra-hard crystals of boron carbide and boron nitride. Boron is synthesized entirely by cosmic ray spallation and supernovae and not by stellar nucleosynthesis, so it is a low-abundance element in the Solar System and in the Earth's crust. It constitutes about 0.001 percent by weight of Earth's crust. It is concentrated on Earth by the water-solubility of its more common naturally occurring compounds, the borate minerals. These are mined industrially as evaporites, such as borax and kernite. The largest known deposits are in Turkey, the largest producer of boron minerals. Elemental boron is a metalloid that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reactions Of Free Borylenes
Reaction may refer to a process or to a response to an action, event, or exposure: Physics and chemistry *Chemical reaction *Nuclear reaction *Reaction (physics), as defined by Newton's third law *Chain reaction (other). Biology and medicine *Adverse drug reaction *Allergic reaction *Reflex, neural reaction *Hypersensitivity, immune reaction *Intolerance (other) *Light reaction (other). Psychology *Emotional, reaction *Reactivity (behaviour) *Proactivity, opposite of reactive behaviour *Reactive attachment disorder. Politics and culture *Reactionary, a political tendency *Reaction video *Commentary (other). Proper names and titles * ''Reaction'' (album), a 1986 album by American R&B singer Rebbie Jackson ** "Reaction" (song), the title song from the Rebbie Jackson album *"Reaction", a single by Dead Letter Circus *ReAction GUI, a GUI toolkit used on AmigaOS *Reaction.life, a political news and commentary website edited by Iain Martin *Rea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
B Lp NBO
B, or b, is the second letter of the Latin-script alphabet, used in the modern English alphabet, the alphabets of other western European languages and others worldwide. Its name in English is ''bee'' (pronounced ), plural ''bees''. It represents the voiced bilabial stop in many languages, including English. In some other languages, it is used to represent other bilabial consonants. History Old English was originally written in runes, whose equivalent letter was beorc , meaning "birch". Beorc dates to at least the 2nd-century Elder Futhark, which is now thought to have derived from the Old Italic alphabets' either directly or via Latin . The uncial and half-uncial introduced by the Gregorian and Irish missions gradually developed into the Insular scripts' . These Old English Latin alphabets supplanted the earlier runes, whose use was fully banned under King Canute in the early 11th century. The Norman Conquest popularised the Carolingian half-uncial forms which latt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
