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Dichlorophenylphosphine
Dichlorophenylphosphine is an organophosphorus compound with the formula C6H5PCl2. This colourless viscous liquid is commonly used in the synthesis of organophosphines. Dichlorophenylphosphine is commercially available. It may be prepared by an electrophilic substitution of benzene by phosphorus trichloride, catalyzed by aluminium chloride. The compound is an intermediate for the synthesis of other chemicals for instance dimethylphenylphosphine: :C6H5PCl2 + 2 CH3MgI → C6H5P(CH3)2 + 2 MgICl Many tertiary phosphines can be prepared by this route. In the McCormack reaction dichlorophenylphosphine adds dienes to give the chlorophospholenium ring. : Reductive coupling of the dichlorophosphine gives the cyclophosphine (PhP)5.{{cite journal , author = Marianne Baudler, Klaus Glinka , title = Monocyclic and Polycyclic Phosphines , journal = Chem. Rev. ''Chemical Reviews'' is peer-reviewed scientific journal published twice per month by the American Chemical Society. It publishe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organophosphorus Compound
Organophosphorus compounds are organic compounds containing phosphorus. They are used primarily in pest control as an alternative to chlorinated hydrocarbons that persist in the environment. Some organophosphorus compounds are highly effective insecticides, although some are extremely toxic to humans, including sarin and VX nerve agents. Organophosphorus chemistry is the corresponding science of the properties and reactivity of organophosphorus compounds. Phosphorus, like nitrogen, is in group 15 of the periodic table, and thus phosphorus compounds and nitrogen compounds have many similar properties. The definition of organophosphorus compounds is variable, which can lead to confusion. In industrial and environmental chemistry, an organophosphorus compound need contain only an organic substituent, but need not have a direct phosphorus-carbon (P-C) bond. Thus a large proportion of pesticides (e.g., malathion), are often included in this class of compounds. Phosphorus can adopt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organophosphine
Organophosphines are organophosphorus compounds with the formula PR''n''H3−''n'', where R is an organic substituent. These compounds can be classified according to the value of ''n'': primary phosphines (''n'' = 1), secondary phosphines (''n'' = 2), tertiary phosphines (''n'' = 3). All adopt pyramidal structures. Organophosphines are generally colorless, lipophilic liquids or solids. The parent of the organophosphines is phosphine (PH3). Annette Schier and Hubert Schmidbaur"P-Donor Ligands" in Encyclopedia of Inorganic Chemistry 2006, Wiley-VCH, Weinheim. 1° vs 2° vs 3° phosphines Organophophines are classified according to the number of organic substituents. Primary phosphines Primary (1°) phosphines, with the formula RPH2, are typically prepared by alkylation of phosphine. Simple alkyl derivatives such as methylphosphine (CH3PH2) are prepared by alkylation of alkali metal derivatives MPH2 (M is lithium, Li, sodium, Na, or potassium, K). A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dimethylphenylphosphine
Dimethylphenylphosphine is an organophosphorus compound with a formula P(C6H5)(CH3)2. The phosphorus is connected to a phenyl group and two methyl groups, making it the simplest aromatic alkylphosphine. It is colorless air sensitive liquid. It is a member of series (CH3)3-n(C6H5)2P that also includes n = 0, n = 2, and n = 3 that are often employed as ligands in metal phosphine complexes. Preparation Dimethylphenylphosphine is prepared by the reaction of methylmagnesium halide with dichlorophenylphosphine. :(C6H5)Cl2P + 2CH3MgBr → (C6H5)(CH3)2P + 2MgBrCl The phosphine is purified by distillation under reduced pressure. A solution of (C6H5)(CH3)2P in CDCl3 shows proton NMR signals at δ 7.0-7.5 and a doublet at δ 1.2. The phosphorus-31 NMR spectrum shows a singlet at -45.9 ppm in CDCl3. Structure and properties Dimethylphenylphosphine is a pyramidal molecule where the phenyl group and two methyl groups are connected to the phosphorus. The bond length and angles a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphole
Phosphole is the organic compound with the chemical formula ; it is the phosphorus analog of pyrrole. The term phosphole also refers to substituted derivatives of the parent heterocycle. These compounds are of theoretical interest but also serve as ligands for transition metals and as precursors to more complex organophosphorus compounds. Triphosphole, , is a heterocycle with 3 phosphorus atoms. Pentaphosphole, , is a cyclic compound with 5 phosphorus atoms. Structure and bonding Unlike the related 5-membered heterocycles pyrrole, thiophene, and furan, the aromaticity of phospholes is diminished, reflecting the reluctance of phosphorus to delocalize its lone pair. The main indication of this difference is the pyramidalization of phosphorus. The absence of aromaticity is also indicated by the reactivity of phospholes. Phospholes undergo different cycloaddition reactions; coordination properties of phospholes are also well studied. Preparation The parent phosphole was first descr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benzene
Benzene is an organic chemical compound with the molecular formula C6H6. The benzene molecule is composed of six carbon atoms joined in a planar ring with one hydrogen atom attached to each. Because it contains only carbon and hydrogen atoms, benzene is classed as a hydrocarbon. Benzene is a natural constituent of petroleum and is one of the elementary petrochemicals. Due to the cyclic continuous pi bonds between the carbon atoms, benzene is classed as an aromatic hydrocarbon. Benzene is a colorless and highly flammable liquid with a sweet smell, and is partially responsible for the aroma of gasoline. It is used primarily as a precursor to the manufacture of chemicals with more complex structure, such as ethylbenzene and cumene, of which billions of kilograms are produced annually. Although benzene is a major industrial chemical, it finds limited use in consumer items because of its toxicity. History Discovery The word "''benzene''" derives from "''gum benzoin''" (benzoin res ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbon Disulfide
Carbon disulfide (also spelled as carbon disulphide) is a neurotoxic, colorless, volatile liquid with the formula and structure . The compound is used frequently as a building block in organic chemistry as well as an industrial and chemical non-polar solvent. It has an "ether-like" odor, but commercial samples are typically contaminated with foul-smelling impurities.. It is of comparable toxicity to carbon monoxide. History In 1796, the German chemist Wilhelm August Lampadius (1772–1842) first prepared carbon disulfide by heating pyrite with moist charcoal. He called it "liquid sulfur" (''flüssig Schwefel''). The composition of carbon disulfide was finally determined in 1813 by the team of the Swedish chemist Jöns Jacob Berzelius (1779–1848) and the Swiss-British chemist Alexander Marcet (1770–1822). Their analysis was consistent with an empirical formula of CS2. Occurrence, manufacture, properties Small amounts of carbon disulfide are released by volcanic eruptio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chloroform
Chloroform, or trichloromethane, is an organic compound with chemical formula, formula Carbon, CHydrogen, HChlorine, Cl3 and a common organic solvent. It is a colorless, strong-smelling, dense liquid produced on a large scale as a precursor to PTFE. It is also a precursor to various refrigerants. It is trihalomethane. It is a powerful anesthetic, euphoriant, anxiolytic, and sedative when inhaled or ingested. Structure The molecule adopts a tetrahedral molecular geometry with C3v symmetry group, symmetry. Natural occurrence The total global flux of chloroform through the environment is approximately tonnes per year, and about 90% of emissions are natural in origin. Many kinds of seaweed produce chloroform, and fungi are believed to produce chloroform in soil. Abiotic processes are also believed to contribute to natural chloroform productions in soils although the mechanism is still unclear. Chloroform volatilizes readily from soil and surface water and undergoes degradation in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Formula
In chemistry, a chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, such as parentheses, dashes, brackets, commas and ''plus'' (+) and ''minus'' (−) signs. These are limited to a single typographic line of symbols, which may include Subscript and superscript, subscripts and superscripts. A chemical formula is not a chemical nomenclature, chemical name, and it contains no words. Although a chemical formula may imply certain simple chemical structures, it is not the same as a full chemical structural formula. Chemical formulae can fully specify the structure of only the simplest of molecules and chemical substances, and are generally more limited in power than chemical names and structural formulae. The simplest types of chemical formulae are called ''empirical formulae'', which use letters and numbers ind ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrophilic Substitution
Electrophilic substitution reactions are chemical reactions in which an electrophile displaces a functional group in a compound, which is typically, but not always, aromatic. Aromatic substitution reactions are characteristic of aromatic compounds and are common ways of introducing functional groups into benzene rings. Some aliphatic compounds can undergo electrophilic substitution as well. Electrophilic aromatic substitution In electrophilic substitution in aromatic compounds, an atom appended to the aromatic ring, usually hydrogen, is replaced by an electrophile. The most important reactions of this type that take place are aromatic nitration, aromatic halogenation, aromatic sulfonation and acylation and alkylating Friedel-Crafts reactions. It further consists of alkylation and acylation. Electrophilic aliphatic substitution In electrophilic substitution in aliphatic compounds, an electrophile displaces a functional group. This reaction is similar to nucleophilic aliphati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphorus Trichloride
Phosphorus trichloride is an inorganic compound with the chemical formula PCl3. A colorless liquid when pure, it is an important industrial chemical, being used for the manufacture of phosphites and other organophosphorus compounds. It is toxic and reacts readily with water to release hydrogen chloride. History Phosphorus trichloride was first prepared in 1808 by the French chemists Joseph Louis Gay-Lussac and Louis Jacques Thénard by heating calomel (Hg2Cl2) with phosphorus. Later during the same year, the English chemist Humphry Davy produced phosphorus trichloride by burning phosphorus in chlorine gas. Preparation World production exceeds one-third of a million tonnes. Phosphorus trichloride is prepared industrially by the reaction of chlorine with white phosphorus, using phosphorus trichloride as the solvent. In this continuous process PCl3 is removed as it is formed in order to avoid the formation of PCl5. :P4 + 6 Cl2 → 4 PCl3 Structure and spectroscopy It has a trig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aluminium Chloride
Aluminium chloride, also known as aluminium trichloride, is an inorganic compound with the formula . It forms hexahydrate with the formula , containing six water molecules of hydration. Both are colourless crystals, but samples are often contaminated with iron(III) chloride, giving a yellow color. The anhydrous material is important commercially. It has a low melting and boiling point. It is mainly produced and consumed in the production of aluminium metal, but large amounts are also used in other areas of the chemical industry. The compound is often cited as a Lewis acid. It is an example of an inorganic compound that reversibly changes from a polymer to a monomer at mild temperature. Structure Anhydrous adopts three structures, depending on the temperature and the state (solid, liquid, gas). Solid has a sheet-like layered structure with cubic close-packed chloride ions. In this framework, the Al centres exhibit octahedral coordination geometry. In contrast, has a more mol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
McCormack Reaction
The McCormack reaction is a method for the synthesis of organophosphorus compounds. In this reaction, a 1,3-diene and a source of R2P+ are combined to give phospholenium cation. The reaction is named after W. B. McCormack, a research chemist at duPont. An illustrative reaction involves phenyldichlorophosphine and isoprene: : The reaction proceeds via a pericyclic +4process. The resulting derivatives can be hydrolyzed to give the phosphine oxide. Dehydrohalogenation gives the phosphole Phosphole is the organic compound with the chemical formula ; it is the phosphorus analog of pyrrole. The term phosphole also refers to substituted derivatives of the parent heterocycle. These compounds are of theoretical interest but also serve a ....Handbook of organophosphorus chemistry by Robert Engel, CRC Press, 1992. {{ISBN, 0-8247-8733-1. References Cycloadditions Cheletropic reactions Name reactions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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