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Trisilaallene
Trisilaallene is a subclass of silene derivatives where a central silicon atom forms double bonds with each of two terminal silicon atoms, with the generic formula R2Si=Si=SiR2. Trisilaallene is a silicon-based analog of an allene, but their chemical properties are markedly different. Synthesis The first isolable trisilaallene compound was reported by Kira ''et al.'' in 2003, synthesized by reductive dehalogenation of tetrachlorosilane using potassium graphite. This tetraalkyl-substituted trisilallene showed thermal stability up to its melting point around 200 °C, but decomposed in contact with air. Its remarkable stability is attributable to bulky substituents providing kinetic protection at the terminal silicon atoms. The 29Si- NMR shifts of the central silicon and terminal silicon atoms were observed at 157.0 ppm and 196.9 ppm respectively. Two Si=Si bond lengths were determined to be 2.177 Å and 2.188 Å by X-ray crystallography, which are within the typical range of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trisilaallene
Trisilaallene is a subclass of silene derivatives where a central silicon atom forms double bonds with each of two terminal silicon atoms, with the generic formula R2Si=Si=SiR2. Trisilaallene is a silicon-based analog of an allene, but their chemical properties are markedly different. Synthesis The first isolable trisilaallene compound was reported by Kira ''et al.'' in 2003, synthesized by reductive dehalogenation of tetrachlorosilane using potassium graphite. This tetraalkyl-substituted trisilallene showed thermal stability up to its melting point around 200 °C, but decomposed in contact with air. Its remarkable stability is attributable to bulky substituents providing kinetic protection at the terminal silicon atoms. The 29Si- NMR shifts of the central silicon and terminal silicon atoms were observed at 157.0 ppm and 196.9 ppm respectively. Two Si=Si bond lengths were determined to be 2.177 Å and 2.188 Å by X-ray crystallography, which are within the typical range of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atomic Orbital
In atomic theory and quantum mechanics, an atomic orbital is a function describing the location and wave-like behavior of an electron in an atom. This function can be used to calculate the probability of finding any electron of an atom in any specific region around the atom's nucleus. The term ''atomic orbital'' may also refer to the physical region or space where the electron can be calculated to be present, as predicted by the particular mathematical form of the orbital. Each orbital in an atom is characterized by a set of values of the three quantum numbers , , and , which respectively correspond to the electron's energy, angular momentum, and an angular momentum vector component (magnetic quantum number). Alternative to the magnetic quantum number, the orbitals are often labeled by the associated harmonic polynomials (e.g., ''xy'', ). Each such orbital can be occupied by a maximum of two electrons, each with its own projection of spin m_s. The simple names s orbital, p orb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermal Rearrangement Of Trisilaallene
A thermal column (or thermal) is a rising mass of buoyant air, a convective current in the atmosphere, that transfers heat energy vertically. Thermals are created by the uneven heating of Earth's surface from solar radiation, and are an example of convection, specifically atmospheric convection. Thermals on Earth The Sun warms the ground, which in turn warms the air directly above. The warm air near the surface expands, becoming less dense than the surrounding air. The lighter air rises and cools due to its expansion in the lower pressure at higher altitudes. It stops rising when it has cooled to the same temperature, thus density, as the surrounding air. Associated with a thermal is a downward flow surrounding the thermal column. The downward-moving exterior is caused by colder air being displaced at the top of the thermal. The size and strength of thermals are influenced by the properties of the lower atmosphere (the ''troposphere''). When the air is cold, bubbles of war ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reaction Of Trisilaallene With Acetone
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reaction Of Trisilaallene With Haloalkane
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charge Distribution In Trisilaallene
Charge or charged may refer to: Arts, entertainment, and media Films * '' Charge, Zero Emissions/Maximum Speed'', a 2011 documentary Music * ''Charge'' (David Ford album) * ''Charge'' (Machel Montano album) * ''Charge!!'', an album by The Aquabats * ''Charged'' (Nebula album) * ''Charged'' (Toshinori Kondo, Eraldo Bernocchi and Bill Laswell album) Television * ''Charge'' (TV series) * Charge! (TV network) * "Charged" (''Reaper''), episode 2 of season one of ''Reaper'' Companies * Charge Automotive Limited, an electric-vehicle manufacturer * Charged Productions, an animation studio * Charged Records, a record label Finance * Equitable charge, confers a right on the secured party to look to a particular asset in the event of the debtor's default * Floating charge, a security interest over the assets of a company Law * Criminal charge, a formal accusation made before a court by a prosecuting authority * Legal charge, information or indictment through a formal legal proc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alcohol Addition To Alkyl-substituted Trisilaallene
Alcohol most commonly refers to: * Alcohol (chemistry), an organic compound in which a hydroxyl group is bound to a carbon atom * Alcohol (drug), an intoxicant found in alcoholic drinks Alcohol may also refer to: Chemicals * Ethanol, one of several alcohols, commonly known as alcohol in everyday life ** Alcoholic beverage, sometimes referred to as "alcohol", any drink containing ethanol ** Surrogate alcohol, any substance containing ethanol that is intentionally consumed by humans but is not meant for human consumption * Methanol, a commodity chemical that can serve as a precursor to other chemicals * Alcohol fuel, a fuel containing alcohols * Alcohol powder, a powdered form of alcohol * Fusel alcohol, a mixture of several alcohols (chiefly amyl alcohol) produced as a by-product of alcoholic fermentation. * Alcohols (medicine), the use of alcohols in medicine ** Rubbing alcohol, a solution of denatured or isopropyl alcohol used in medicine Music * "Alcohol" (Barenaked Ladi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frontier Orbitals Of Silyl-substituted Trisilaallene
A frontier is the political and geographical area near or beyond a boundary. A frontier can also be referred to as a "front". The term came from French in the 15th century, with the meaning "borderland"—the region of a country that fronts on another country (see also marches). Unlike a border—a rigid and clear-cut form of state boundary—in the most general sense a frontier can be fuzzy or diffuse. For example, the frontier between the Eastern United States and the Old West in the 1800s was an area where European American settlements gradually thinned out and gave way to Native American settlements or uninhabited land. The frontier was not always a single continuous area, as California and various large cities were populated before the land that connected those to the East. Frontiers and borders also imply different geopolitical strategies. In Ancient Rome, the Roman Republic experienced a period of active expansion and creating new frontiers. From the reign of Augus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LUMO
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.'' 2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HOMO
''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 ye ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frontier Orbitals Of Alkyl-substituted Trisilaallene
A frontier is the political and geographical area near or beyond a boundary. A frontier can also be referred to as a "front". The term came from French in the 15th century, with the meaning "borderland"—the region of a country that fronts on another country (see also marches). Unlike a border—a rigid and clear-cut form of state boundary—in the most general sense a frontier can be fuzzy or diffuse. For example, the frontier between the Eastern United States and the Old West in the 1800s was an area where European American settlements gradually thinned out and gave way to Native American settlements or uninhabited land. The frontier was not always a single continuous area, as California and various large cities were populated before the land that connected those to the East. Frontiers and borders also imply different geopolitical strategies. In Ancient Rome, the Roman Republic experienced a period of active expansion and creating new frontiers. From the reign of Augus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zwitterion
In chemistry, a zwitterion ( ; ), also called an inner salt or dipolar ion, is a molecule that contains an equal number of positively- and negatively-charged functional groups. : With amino acids, for example, in solution a chemical equilibrium will be established between the "parent" molecule and the zwitterion. Betaines are zwitterions that cannot isomerize to an all-neutral form, such as when the positive charge is located on a quaternary ammonium group. Similarly, a molecule containing a phosphonium group and a carboxylate group cannot isomerize. Amino acids The equilibrium is established in two stages. In the first stage, a proton is transferred from the carboxyl group to a water molecule: :H2N(R)CO2H + H2O H2N(R)CO2- + H3O+ In the second stage, a proton is transferred from the hydronium ion to the amine group: :H2N(R)CO2- + H3O+ H3N+ (R)CO2- + H2O Overall, the reaction is an isomerization reaction :H2N(R)CO2H H3N+ (R)CO2- The ratio of the concentrations of the two spec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
