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Diphosphane
Diphosphane, or diphosphine, is an inorganic compound with the chemical formula P2H4. This colourless liquid is one of several binary phosphorus hydrides. It is the impurity that typically causes samples of phosphine to ignite in air. Properties, preparation, reactions Diphosphane adopts the gauche conformation (like hydrazine, less symmetrical than shown in the image) with a P−P distance of 2.219 angstroms. It is nonbasic, unstable at room temperature, and spontaneously flammable in air. It is only poorly soluble in water but dissolves in organic solvents. Its 1H NMR spectrum consists of 32 lines resulting from an A2XX'A'2 splitting system. Diphosphane is produced by the hydrolysis of calcium monophosphide, which can be described as the Ca2+ derivative of . According to an optimized procedure, hydrolysis of 400 g of CaP at −30 °C gives about 20 g of product, slightly contaminated with phosphine. Reaction of diphosphane with butyllithium affords a variety of conde ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diphosphines
Diphosphines, sometimes called bisphosphanes, are organophosphorus compounds most commonly used as bidentate phosphine ligands in inorganic and organometallic chemistry. They are identified by the presence of two phosphino groups linked by a backbone, and are usually chelating. A wide variety of diphosphines have been synthesized with different linkers and R-groups. Alteration of the linker and R-groups alters the electronic and steric properties of the ligands which can result in different coordination geometries and catalytic behavior in homogeneous catalysts. Synthesis 222px, Chlorodiisopropylphosphine is a popular building block for the preparation of diphosphines. From phosphide building blocks Many widely used diphosphine ligands have the general formula Ar2P(CH2)nPAr2. These compounds can be prepared from the reaction of X(CH2)nX (X=halogen) and MPPh2 (M = alkali metal): :Cl(CH2)nCl + 2 NaPPh2 → Ph2P(CH2)nPPh2 + 2 NaCl Diphosphine ligands can also be prepa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrazine
Hydrazine is an inorganic compound with the chemical formula . It is a simple pnictogen hydride, and is a colourless flammable liquid with an ammonia-like odour. Hydrazine is highly toxic unless handled in solution as, for example, hydrazine hydrate (). Hydrazine is mainly used as a foaming agent in preparing polymer foams, but applications also include its uses as a precursor to polymerization catalysts, pharmaceuticals, and agrochemicals, as well as a long-term storable propellant for in-space spacecraft propulsion. Additionally, hydrazine is used in various rocket fuels and to prepare the gas precursors used in air bags. Hydrazine is used within both nuclear and conventional electrical power plant steam cycles as an oxygen scavenger to control concentrations of dissolved oxygen in an effort to reduce corrosion. the world hydrazine hydrate market amounted to $350 million. About two million tons of hydrazine hydrate were used in foam blowing agents in 2015. Hydra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triazane
Triazane is an inorganic compound with the chemical formula or . Triazane is the third simplest acyclic azane after ammonia and hydrazine. It can be synthesized from hydrazine but is unstable and cannot be isolated in the free base form, only as salt forms such as triazanium sulfate. Attempts to convert triazanium salts to the free base release only diazene and ammonia. Triazane was first synthesized as a ligand of the silver complex ion: tris(μ2-triazane-κ2''N''1,''N''3)disilver(2+). Triazane has also been synthesized in electron-irradiated ammonia ices and detected as a stable gas-phase product after sublimation.Forstel, Maksyutenko, Jones, Sun, Chen, Chang, & Kaiser. "Detection of the Elusive Triazane Molecule () in the Gas Phase", ''ChemPhysChem'', 2015, 16, 3139. Compounds containing the triazane skeleton Several compounds containing the triazane skeleton are known, including 1-methyl-1-nitrosohydrazine (), produced from the solventless reaction of methylhydrazine () a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pnictogen Hydride
Pnictogen hydrides or hydrogen pnictides are binary compounds of hydrogen with pnictogen ( or ; from grc, πνῑ́γω "to choke" and -gen, "generator") atoms (elements of group 15: nitrogen, phosphorus, arsenic, antimony, and bismuth) covalently bonded to hydrogen. Pnictogen trihydrides The simplest series has the chemical formula XH3 (less commonly H3X), with X representing any of the pnictogens. They take on the pyramidal structure (as opposed to the trigonal planar arrangement of the group 13 hydrides), and therefore are polar. These pnictogen trihydrides are generally increasingly unstable and poisonous with heavier elements. Like the simple hydrogen halides and chalcogenides, the pnictogen hydrides are water- soluble. Unlike other hydrides such as hydrogen sulfide and hydrogen fluoride, which form acidic aqueous solutions, ammonia dissolves in water to make ammonium hydroxide which is basic (by forming a hydroxide ion as opposed to hydronium). Phosphine is also water-s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphane
Phosphine (IUPAC name: phosphane) is a colorless, flammable, highly toxic compound with the chemical formula , classed as a pnictogen hydride. Pure phosphine is odorless, but technical grade samples have a highly unpleasant odor like rotting fish, due to the presence of substituted phosphine and diphosphane (). With traces of present, is spontaneously flammable in air (pyrophoric), burning with a luminous flame. Phosphine is a highly toxic respiratory poison, and is immediately dangerous to life or health at 50 ppm. Phosphine has a trigonal pyramidal structure. Phosphines are compounds that include and the organophosphines, which are derived from by substituting one or more hydrogen atoms with organic groups. They have the general formula . Phosphanes are saturated phosphorus hydrides of the form , such as triphosphane. Phosphine, PH3, is the smallest of the phosphines and the smallest of the phosphanes. History Philippe Gengembre (1764–1838), a student of Lavoisier, f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diphosphenes
Diphosphene is a type of organophosphorus compound that has a phosphorus–phosphorus double bond, denoted by R-P=P-R'. These compounds are not common but are of theoretical interest. Normally, compounds with the empirical formula RP exist as rings. However, like other multiple bonds between heavy main-group elements, P=P double bonds can be stabilized by a large steric hindrance from the substitutions. The first isolated diphosphene bis(2,4,6-tri-tert-butylphenyl)diphosphene was exemplified by Masaaki Yoshifuji and his coworkers in 1981, in which diphosphene is stabilized by two bulky phenyl group. Synthesis Synthesis of aryl-substituted diphosphene In 1877, Köhler and Michaelis claimed that they synthesized the first isolated diphosphene (PhP=PPh). However, the molecular weight determination and X-ray crystallographic analysis later proved that this "diphosphene" only had a P-P single bond. Then the research to diphosphenes kept silent over almost 20 years until Masaa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrophoricity
A substance is pyrophoric (from grc-gre, πυροφόρος, , 'fire-bearing') if it ignites spontaneously in air at or below (for gases) or within 5 minutes after coming into contact with air (for liquids and solids). Examples are organolithium compounds and triethylborane. Pyrophoric materials are often water-reactive as well and will ignite when they contact water or humid air. They can be handled safely in atmospheres of argon or (with a few exceptions) nitrogen. Class D fire extinguishers are designated for use in fires involving pyrophoric materials. A related concept is hypergolicity, in which two compounds spontaneously ignite when mixed. Uses The creation of sparks from metals is based on the pyrophoricity of small metal particles, and pyrophoric alloys are made for this purpose. The sparking mechanisms in lighters and various toys, using ferrocerium; starting fires without matches, using a firesteel; the flintlock mechanism in firearms; and spark testing fe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphine
Phosphine (IUPAC name: phosphane) is a colorless, flammable, highly toxic compound with the chemical formula , classed as a pnictogen hydride. Pure phosphine is odorless, but technical grade samples have a highly unpleasant odor like rotting fish, due to the presence of substituted phosphine and diphosphane (). With traces of present, is spontaneously flammable in air ( pyrophoric), burning with a luminous flame. Phosphine is a highly toxic respiratory poison, and is immediately dangerous to life or health at 50 ppm. Phosphine has a trigonal pyramidal structure. Phosphines are compounds that include and the organophosphines, which are derived from by substituting one or more hydrogen atoms with organic groups. They have the general formula . Phosphanes are saturated phosphorus hydrides of the form , such as triphosphane. Phosphine, PH3, is the smallest of the phosphines and the smallest of the phosphanes. History Philippe Gengembre (1764–1838), a student of Lavois ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Angstrom
The angstromEntry "angstrom" in the Oxford online dictionary. Retrieved on 2019-03-02 from https://en.oxforddictionaries.com/definition/angstrom.Entry "angstrom" in the Merriam-Webster online dictionary. Retrieved on 2019-03-02 from https://www.merriam-webster.com/dictionary/angstrom. (, ; , ) or ångström is a metric unit of length equal to m; that is, one ten-billionth ( US) of a metre, a hundred-millionth of a centimetre,Entry "angstrom" in the Oxford English Dictionary, 2nd edition (1986). Retrieved on 2021-11-22 from https://www.oed.com/oed2/00008552. 0.1 nanometre, or 100 picometres. Its symbol is Å, a letter of the Swedish alphabet. The unit is named after the Swedish physicist Anders Jonas Ångström (1814–1874). The angstrom is often used in the natural sciences and technology to express sizes of atoms, molecules, microscopic biological structures, and lengths of chemical bonds, arrangement of atoms in crystals,Arturas Vailionis (2015):Geometry of Crystals L ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thiophosphoryl Chloride
Thiophosphoryl chloride is an inorganic compound with the formula PSCl3.Spilling, C. D. "Thiophosphoryl Chloride" in Encyclopedia of Reagents for Organic Synthesis John Wiley & Sons, Weinheim, 2001. . Article Online Posting Date: April 15, 2001. It is a colorless pungent smelling liquid that fumes in air. It is synthesized from phosphorus chloride and used to thiophosphorylate organic compounds, such as to produce insecticides. Synthesis Thiophosphoryl chloride can be generated by several reactions starting from phosphorus trichloride. The most common and practical synthesis, hence used in industrial manufacturing, is directly reacting phosphorus trichloride with excess sulfur at 180 °C.. :PCl3 + S → PSCl3 Using this method, yields can be very high after purification by distillation. Catalysts facilitate the reaction at lower temperatures, but are not usually necessary. Alternatively, it is obtained by combining phosphorus pentasulfide and phosphorus pentachloride.M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chlorodiphenylphosphine
Chlorodiphenylphosphine is an organophosphorus compound with the formula (C6H5)2PCl, abbreviated Ph2PCl. It is a colourless oily liquid with a pungent odor that is often described as being garlic-like and detectable even in the ppb range. It is useful reagent for introducing the Ph2P group into molecules, which includes many ligands.Quin, L. D. ''A Guide to Organophosphorus Chemistry''; Wiley IEEE: New York, 2000; pp 44-69. Like other halophosphines, Ph2PCl is reactive with many nucleophiles such as water and easily oxidized even by air. Synthesis and reactions Chlorodiphenylphosphine is produced on a commercial scale from benzene and phosphorus trichloride (PCl3). Benzene reacts with phosphorus trichloride at extreme temperatures around 600 °C to give dichlorophenylphosphine (PhPCl2) and HCl. Redistribution of PhPCl2 in the gas phase at high temperatures results in chlorodiphenylphosphine. :2PhPCl2 → Ph2PCl + PCl3 Alternatively such compounds are prepared by redistribu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetraphenyldiphosphine
Tetraphenyldiphosphine is the organophosphorus compound with the formula Ph2sub>2, where Ph = phenyl In organic chemistry, the phenyl group, or phenyl ring, is a cyclic group of atoms with the formula C6 H5, and is often represented by the symbol Ph. Phenyl group is closely related to benzene and can be viewed as a benzene ring, minus a hydrogen ... (C6H5). It is a white, air-sensitive solid that dissolves in nonpolar solvents. It is a centrosymmetric molecule with a P-P bond of 2.2592 Å. Tetraphenyldiphosphine is produced by reductive coupling of chlorodiphenylphosphine: :2 Ph2PCl + 2 Na → Ph2P-PPh2 + 2 NaCl The compound is used as a source of the Ph2P− group.{{cite journal, title=Zur Kenntnis der Organophosphorverbindungen, III. Umsetzungen mit Diphenylphosphin‐natrium , first1=Wilhelm , last1=Kuchen, first2=Hans, last2=Buchwald, journal=Chem. Ber., volume=92, pages=227–231 , year=1959, doi=10.1002/cber.19590920126 :Ph2P-PPh2 + 2 Na → + 2 NaPPh2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
