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Tetrachlorocyclopropene
Tetrachlorocyclopropene is a chemical compound with the formula C3Cl4. A colorless liquid, the compound is a reagent used to prepare acetylene derivatives and in organic synthesis. It is prepared by addition of dichlorocarbene to trichloroethylene.{{cite journal, last1=Glück, first1=C, last2=Poingée, first2=V, last3=Schwager, first3=H, title=Improved Synthesis of 7,7-Difluorocyclopropabenzene, journal=Synthesis, volume=1987, issue=3, year=1987, pages=260–262, doi=10.1055/s-1987-27908, url=https://www.thieme-connect.com/products/ejournals/abstract/10.1055/s-1987-27908 The compound is used to prepare arylpropiolic acids: :C3Cl4 + ArH + 2 H2O → ArC2CO2H + 4 HCl Under some circumstances, diarylation occurs, giving diarylcyclopropenones, which decarbonylate to give diarylacetylenes. These reactions are thought to proceed via the intermediacy of trichlorocyclopropenium The cyclopropenium ion is the cation with the formula . It has attracted attention as the smallest e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclopropenium
The cyclopropenium ion is the cation with the formula . It has attracted attention as the smallest example of an aromatic cation. Its salts have been isolated, and many derivatives have been characterized by X-ray crystallography. The cation and some simple derivatives have been identified in the atmosphere of the Saturnian moon Titan. Bonding With two π electrons, the cyclopropenium cation class obeys Hückel’s rules of aromaticity for electrons since, in this case, ''n'' = 0. Consistent with this prediction, the C3H3 core is planar and the C–C bonds are equivalent. In the case of the cation in 3(SiMe3)3sup>+, the ring C–C distances range from 1.374(2) to 1.392(2) Å. Syntheses Salts of many cyclopropenyl cations have been characterized. Their stability varies according to the steric and inductive effects of the substituents. Salts of triphenylcyclopropenium were first reported by Ronald Breslow in 1957. The salt was prepared in two steps starting with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Compound
A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element is therefore not a compound. A compound can be transformed into a different substance by a chemical reaction, which may involve interactions with other substances. In this process, bonds between atoms may be broken and/or new bonds formed. There are four major types of compounds, distinguished by how the constituent atoms are bonded together. Molecular compounds are held together by covalent bonds; ionic compounds are held together by ionic bonds; intermetallic compounds are held together by metallic bonds; coordination complexes are held together by coordinate covalent bonds. Non-stoichiometric compounds form a disputed marginal case. A chemical formula specifies the number of atoms of each element in a compound molecule, using the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dichlorocarbene
Dichlorocarbene is the reactive intermediate with chemical formula CCl2. Although this chemical species has not been isolated, it is a common intermediate in organic chemistry, being generated from chloroform. This bent diamagnetic molecule rapidly inserts into other bonds. Preparation Dichlorocarbene is most commonly generated by reaction of chloroform and a base such as potassium ''tert''-butoxide or aqueous sodium hydroxide. A phase transfer catalyst, for instance benzyltriethylammonium bromide, facilitates the migration of the hydroxide in the organic phase. :HCCl3 + NaOH → CCl2 + NaCl + H2O Other reagents and routes Another precursor to dichlorocarbene is ethyl trichloroacetate. Upon treatment with sodium methoxide it releases CCl2. Phenyl(trichloromethyl)mercury decomposes thermally to release CCl2. :PhHgCCl3 → CCl2 + PhHgCl Dichlorodiazirine, which is stable in the dark, decomposes into dichlorocarbene and nitrogen via photolysis. Dichlorocarbene can also be obta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trichloroethylene
The chemical compound trichloroethylene is a halocarbon commonly used as an industrial solvent. It is a clear, colourless non-flammable liquid with a chloroform-like sweet smell. It should not be confused with the similar 1,1,1-trichloroethane, which is commonly known as ''chlorothene''. The IUPAC name is trichloroethene. Industrial abbreviations include TCE, trichlor, Trike, Tricky and tri. It has been sold under a variety of trade names. Under the trade names Trimar and Trilene, trichloroethylene was used as a volatile anesthetic and as an inhaled obstetrical analgesic in millions of patients. Groundwater and drinking water contamination from industrial discharge including trichloroethylene is a major concern for human health and has precipitated numerous incidents and lawsuits. History Pioneered by Imperial Chemical Industries in Britain, its development was hailed as an anesthetic revolution. Originally thought to possess less hepatotoxicity than chloroform, and without th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Propiolic Acid
Propiolic acid is the organic compound with the formula HC2CO2H. It is the simplest acetylenic carboxylic acid. It is a colourless liquid that crystallises to give silky crystals. Near its boiling point, it decomposes. It is soluble in water and possesses an odor like that of acetic acid. Preparation It is prepared commercially by oxidizing propargyl alcohol at a lead electrode. It can also be prepared by decarboxylation of acetylenedicarboxylic acid. : Reactions and applications Exposure to sunlight converts it into trimesic acid (benzene-1,3,5-tricarboxylic acid). It undergoes bromination to give dibromoacrylic acid. With hydrogen chloride it forms chloroacrylic acid. Its ethyl ester condenses with hydrazine to form pyrazolone. It forms a characteristic explosive solid upon treatment to its aqueous solution with ammoniacal silver nitrate. An amorphous explosive precipitate forms with ammoniacal cuprous chloride. Propiolates Propiolates are esters or salts of propiolic a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diphenylacetylene
Diphenylacetylene is the chemical compound C6H5C≡CC6H5. The molecule consists of two phenyl groups attached to a C2 unit. A colorless solid, it is used as a building block in organic synthesis and as a ligand in organometallic chemistry. Preparation and structure In one preparation for this compound, benzil is condensed with hydrazine to give the bis(hydrazone), which is oxidized with mercury(II) oxide. Alternatively stilbene is brominated, and the resulting dibromodiphenylethane is subjected to dehydrohalogenation, Yet another method starts involves the coupling iodobenzene and the copper salt of phenylacetylene in the Castro-Stephens coupling. Diphenylacetylene is a planar molecule. The central C≡C distance is 119.8 picometers. Derivatives Reaction of diphenylacetylene with tetraphenylcyclopentadienone results in the formation of hexaphenylbenzene in a Diels–Alder reaction. Reaction of Ph2C2 with benzal chloride in the presence of potassium ''t''-butoxide affords t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organochlorides
An organochloride, organochlorine compound, chlorocarbon, or chlorinated hydrocarbon is an organic compound containing at least one covalently bonded atom of chlorine. The chloroalkane class (alkanes with one or more hydrogens substituted by chlorine) provides common examples. The wide structural variety and divergent chemical properties of organochlorides lead to a broad range of names, applications, and properties. Organochlorine compounds have wide use in many applications, though some are of profound environmental concern, with TCDD being one of the most notorious. Physical and chemical properties Chlorination modifies the physical properties of hydrocarbons in several ways. These compounds are typically denser than water due to the higher atomic weight of chlorine versus hydrogen. Aliphatic organochlorides are often alkylating agents as chlorine can act as a leaving group, which can result in cellular damage. Natural occurrence Many organochlorine compounds have been isolate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
