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Gallane
Gallane, also systematically named trihydridogallium, is an inorganic compound of gallium with the chemical formula (also written as ). It is a photosensitive, colourless gas that cannot be concentrated in pure form. Gallane is both the simplest member of the gallanes, and the prototype of the monogallanes. It has no economic uses, and is only intentionally produced for academic reasons. It has been detected as a transient species in the gas phase;The Chemistry of Aluminium, Gallium, Indium and Thallium, Anthony John Downs, 1993, , also at low temperature (3.5 K) following the reaction of laser ablated gallium atoms and dihydrogen, and more recently in an argon matrix doped with vapour over solid digallane, Ga2H6. Structure of monomeric GaH3 I.R spectroscopic studies indicate that monomeric GaH3 has a trigonal planar structure. Theoretical Ga-H bond lengths have been calculated as being in the range 155.7 pm to 158.7 pm. Monomeric GaH3 dimerises in the vapor phase to form Ga2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digallane
Digallane (systematically named digallane(6)) is an inorganic compound with the chemical formula (also written or ). It is the dimer of the monomeric compound gallane. The eventual preparation of the pure compound, reported in 1989, was hailed as a "tour de force." Digallane had been reported as early as 1941 by Wiberg; however, this claim could not be verified by later work by Greenwood and others. This compound is a colorless gas that decomposes above 0 °C. Preparation A two-stage approach proved to be the key to successful synthesis of pure digallane. Firstly the dimeric monochlorogallane, (H2GaCl)2 (containing bridging chlorine atoms and thus formulated as (H2Ga(μ-Cl))2) was prepared via the hydrogenation of gallium trichloride, GaCl3, with Me3SiH. This step was followed by a further reduction with LiGaH4, solvent free, at −23 °C, to produce digallane, Ga2H6 in low yield. :Ga2Cl6 + 4 Me3SiH → (H2GaCl)2 + 4 Me3SiCl :1/2 (H2GaCl)2 + LiGaH4 → Ga2H6 + LiCl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digallane
Digallane (systematically named digallane(6)) is an inorganic compound with the chemical formula (also written or ). It is the dimer of the monomeric compound gallane. The eventual preparation of the pure compound, reported in 1989, was hailed as a "tour de force." Digallane had been reported as early as 1941 by Wiberg; however, this claim could not be verified by later work by Greenwood and others. This compound is a colorless gas that decomposes above 0 °C. Preparation A two-stage approach proved to be the key to successful synthesis of pure digallane. Firstly the dimeric monochlorogallane, (H2GaCl)2 (containing bridging chlorine atoms and thus formulated as (H2Ga(μ-Cl))2) was prepared via the hydrogenation of gallium trichloride, GaCl3, with Me3SiH. This step was followed by a further reduction with LiGaH4, solvent free, at −23 °C, to produce digallane, Ga2H6 in low yield. :Ga2Cl6 + 4 Me3SiH → (H2GaCl)2 + 4 Me3SiCl :1/2 (H2GaCl)2 + LiGaH4 → Ga2H6 + LiCl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lithium Tetrahydridogallate
Lithium tetrahydridogallate is the inorganic compound with formula LiGaH4. It is a white solid similar to but less thermally robust than lithium aluminium hydride. Synthesis Lithium tetrahydridogallate was first reported by Finholt, Bond and Schlesinger. It is prepared by the reaction of lithium hydride and an ethereal solution of gallium trichloride: : GaCl3 + 4 LiH → LiGaH4 + 3 LiCl The reactants are combined at -80 °C and then allowed to get to room temperature. Higher yields (80-95%) and reaction rates are possible by using gallium tribromide. Properties Lithium tetrahydridogallate is easily dissolved in diethyl ether with which it forms a stable complex, making removal of the solvent difficult. Ethereal solutions of LiGaH4 are indefinitely stable if sealed in glass vessels at 0 °C. Lithium tetrahydridogallate can also be dissolved in tetrahydrofuran and diglyme. Lithium tetrahydridogallate slowly decomposes at room temperature. The decomposition is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gallium
Gallium is a chemical element with the symbol Ga and atomic number 31. Discovered by French chemist Paul-Émile Lecoq de Boisbaudran in 1875, Gallium is in group 13 of the periodic table and is similar to the other metals of the group (aluminium, indium, and thallium). Elemental gallium is a soft, silvery metal in standard temperature and pressure. In its liquid state, it becomes silvery white. If too much force is applied, the gallium may fracture conchoidally. Since its discovery in 1875, gallium has widely been used to make alloys with low melting points. It is also used in semiconductors, as a dopant in semiconductor substrates. The melting point of gallium is used as a temperature reference point. Gallium alloys are used in thermometers as a non-toxic and environmentally friendly alternative to mercury, and can withstand higher temperatures than mercury. An even lower melting point of , well below the freezing point of water, is claimed for the alloy galinstan (62– ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aluminium Hydride
Aluminium hydride (also known as alane and alumane) is an inorganic compound with the formula Al H3. Alane and its derivatives are common reducing (hydride addition) reagents in organic synthesis that are used in solution at both laboratory and industrial scales. In solution—typically in etherial solvents such tetrahydrofuran or diethyl ether—aluminium hydride forms complexes with Lewis bases, and reacts selectively with particular organic functional groups (e.g., with carboxylic acids and esters over organic halides and nitro groups), and although it is not a reagent of choice, it can react with carbon-carbon multiple bonds (i.e., through hydroalumination). Given its density, and with hydrogen content on the order of 10% by weight, some forms of alane are, as of 2016, active candidates for storing hydrogen and so for power generation in fuel cell applications, including electric vehicles. As of 2006 it was noted that further research was required to identify an efficient, e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alumane
Aluminium hydride (also known as alane and alumane) is an inorganic compound with the formula Al H3. Alane and its derivatives are common reducing (hydride addition) reagents in organic synthesis that are used in solution at both laboratory and industrial scales. In solution—typically in etherial solvents such tetrahydrofuran or diethyl ether—aluminium hydride forms complexes with Lewis bases, and reacts selectively with particular organic functional groups (e.g., with carboxylic acids and esters over organic halides and nitro groups), and although it is not a reagent of choice, it can react with carbon-carbon multiple bonds (i.e., through hydroalumination). Given its density, and with hydrogen content on the order of 10% by weight, some forms of alane are, as of 2016, active candidates for storing hydrogen and so for power generation in fuel cell applications, including electric vehicles. As of 2006 it was noted that further research was required to identify an efficient, e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogen
Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic, and highly combustible. Hydrogen is the most abundant chemical substance in the universe, constituting roughly 75% of all normal matter.However, most of the universe's mass is not in the form of baryons or chemical elements. See dark matter and dark energy. Stars such as the Sun are mainly composed of hydrogen in the plasma state. Most of the hydrogen on Earth exists in molecular forms such as water and organic compounds. For the most common isotope of hydrogen (symbol 1H) each atom has one proton, one electron, and no neutrons. In the early universe, the formation of protons, the nuclei of hydrogen, occurred during the first second after the Big Bang. The emergence of neutral hydrogen atoms throughout the universe occurred about 370,000 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methyl Group
In organic chemistry, a methyl group is an alkyl derived from methane, containing one carbon atom bonded to three hydrogen atoms, having chemical formula . In formulas, the group is often abbreviated as Me. This hydrocarbon group occurs in many organic compounds. It is a very stable group in most molecules. While the methyl group is usually part of a larger molecule, bounded to the rest of the molecule by a single covalent bond (), it can be found on its own in any of three forms: methanide anion (), methylium cation () or methyl radical (). The anion has eight valence electrons, the radical seven and the cation six. All three forms are highly reactive and rarely observed. Methyl cation, anion, and radical Methyl cation The methylium cation () exists in the gas phase, but is otherwise not encountered. Some compounds are considered to be sources of the cation, and this simplification is used pervasively in organic chemistry. For example, protonation of methanol gives an elect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trimethylamine
Trimethylamine (TMA) is an organic compound with the formula N(CH3)3. It is a colorless, hygroscopic, and flammable tertiary amine. It is a gas at room temperature but is usually sold as a 40% solution in water. (It is also sold in pressurized gas cylinders.) TMA is a nitrogenous base and can be readily protonated to give the trimethylammonium cation. Trimethylammonium chloride is a hygroscopic colorless solid prepared from hydrochloric acid. Trimethylamine is a good nucleophile, and this reaction is the basis of most of its applications. TMA is widely used in industry: it is used in the synthesis of choline, tetramethylammonium hydroxide, plant growth regulators or herbicides, strongly basic anion exchange resins, dye leveling agents, and a number of basic dyes. At higher concentrations it has an ammonia-like odor, and can cause necrosis of mucous membranes on contact. At lower concentrations, it has a "fishy" odor, the odor associated with rotting fish. In humans, ingesti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adduct
An adduct (from the Latin ''adductus'', "drawn toward" alternatively, a contraction of "addition product") is a product of a direct addition of two or more distinct molecules, resulting in a single reaction product containing all atoms of all components. The resultant is considered a distinct molecular species. Examples include the addition of sodium bisulfite to an aldehyde to give a sulfonate. It can just be considered as a single product resulting from the direct combination of different molecules which comprises all the reactant molecules' atoms. Adducts often form between Lewis acids and Lewis bases. A good example is the formation of adducts between the Lewis acid borane and the oxygen atom in the Lewis bases, tetrahydrofuran (THF): BH3·O(CH2)4 or diethyl ether: BH3·O(CH3CH2)2. Many Lewis acids and Lewis bases reacting in the gas phase or in non-aqueous solvents to form adducts have been examined in the ECW model. Trimethylboron, trimethyltin chloride and bis(hexaflu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lewis Acids And Bases
A Lewis acid (named for the American physical chemist Gilbert N. Lewis) is a chemical species that contains an empty orbital which is capable of accepting an electron pair from a Lewis base to form a Lewis adduct. A Lewis base, then, is any species that has a filled orbital containing an electron pair which is not involved in bonding but may form a dative bond with a Lewis acid to form a Lewis adduct. For example, NH3 is a Lewis base, because it can donate its lone pair of electrons. Trimethylborane (Me3B) is a Lewis acid as it is capable of accepting a lone pair. In a Lewis adduct, the Lewis acid and base share an electron pair furnished by the Lewis base, forming a dative bond. In the context of a specific chemical reaction between NH3 and Me3B, a lone pair from NH3 will form a dative bond with the empty orbital of Me3B to form an adduct NH3•BMe3. The terminology refers to the contributions of Gilbert N. Lewis. From p. 142: "We are inclined to think of substances as pos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diethyl Ether
Diethyl ether, or simply ether, is an organic compound in the ether class with the formula , sometimes abbreviated as (see Pseudoelement symbols). It is a colourless, highly volatile, sweet-smelling ("ethereal odour"), extremely flammable liquid. It is commonly used as a solvent in laboratories and as a starting fluid for some engines. It was formerly used as a general anesthetic, until non-flammable drugs were developed, such as halothane. It has been used as a recreational drug to cause intoxication. Production Most diethyl ether is produced as a byproduct of the vapor-phase hydration of ethylene to make ethanol. This process uses solid-supported phosphoric acid catalysts and can be adjusted to make more ether if the need arises. Vapor-phase dehydration of ethanol over some alumina catalysts can give diethyl ether yields of up to 95%. Diethyl ether can be prepared both in laboratories and on an industrial scale by the acid ether synthesis. Ethanol is mixed with a stro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
