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Carbon Oxohalide
Carbon oxohalides are a group of chemical compounds that contain only carbon, oxygen and halogen atoms: fluorine, chlorine, bromine and iodine. They include carbonyl halides, COX2, and oxalyl halides, C2X2O2, where X = F, Cl, Br or I. The halogen atoms X do not have to be identical; they differ in mixed oxohalides. Most combinations of halogens exist but carbonyl iodide, COI2, is unknown. The carbon–oxygen bond length in carbonyl halides (1.13–1.17 Å) is shorter than in other carbonyl compounds such as aldehydes and ketones, carboxylic acids, esters and amides (1.20–1.21 Å). They are reactive reagents for halogenation, acylation and dehydration reactions. See also * Oxohalide * Carbon compounds#Carbon halides * Carbon compounds#Carbon-oxygen compounds * Oxocarbon In chemistry, an oxocarbon or oxide of carbon is a chemical compound consisting only of carbon and oxygen. The simplest and most common oxocarbons are carbon monoxide (CO) and carbon dioxide (). Many other ... [...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] |
CRC Handbook Of Chemistry And Physics
The ''CRC Handbook of Chemistry and Physics'' is a comprehensive one-volume reference resource for science research. First published in 1914, it is currently () in its 103rd edition, published in 2022. It is sometimes nicknamed the "Rubber Bible" or the "Rubber Book", as CRC originally stood for "Chemical Rubber Company". As late as the 1962–1963 edition (3604 pages) the ''Handbook'' contained myriad information for every branch of science and engineering. Sections in that edition include: Mathematics, Properties and Physical Constants, Chemical Tables, Properties of Matter, Heat, Hygrometric and Barometric Tables, Sound, Quantities and Units, and Miscellaneous. Earlier editions included sections such as "Antidotes of Poisons", "Rules for Naming Organic Compounds", "Surface Tension of Fused Salts", "Percent Composition of Anti-Freeze Solutions", "Spark-gap Voltages", "Greek Alphabet", "Musical Scales", "Pigments and Dyes", "Comparison of Tons and Pounds", "Twist Drill and St ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbon Compounds
Carbon compounds are defined as chemical substances containing carbon. More compounds of carbon exist than any other chemical element except for hydrogen. Organic carbon compounds are far more numerous than inorganic carbon compounds. In general bonds of carbon with other elements are covalent bonds. Carbon is tetravalent but carbon free radicals and carbenes occur as short-lived intermediates. Ions of carbon are carbocations and carbanions are also short-lived. An important carbon property is catenation as the ability to form long carbon chains and rings. Allotropes of carbon The known inorganic chemistry of the allotropes of carbon (diamond, graphite, and the fullerenes) blossomed with the discovery of buckminsterfullerene in 1985, as additional fullerenes and their various derivatives were discovered. One such class of derivatives is inclusion compounds, in which an ion is enclosed by the all-carbon shell of the fullerene. This inclusion is denoted by the "@" symbol in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxohalide
In chemistry, molecular oxohalides (oxyhalides) are a group of chemical compounds in which both oxygen and halogen atoms are attached to another chemical element A in a single molecule. They have the general formula , where X = fluorine (F), chlorine (Cl), bromine (Br), and/or iodine (I). The element A may be a main group element, a transition element or an actinide. The term ''oxohalide'', or ''oxyhalide'', may also refer to minerals and other crystalline substances with the same overall chemical formula, but having an ionic structure. Synthesis Oxohalides can be seen as compounds intermediate between oxides and halides. There are three general methods of synthesis: *Partial oxidation of a halide: *:2 PCl3 + O2 -> 2 POCl3 **In this example, the oxidation state increases by two and the electrical charge is unchanged. *Partial halogenation of an oxide: *:2 V2O5 + 6 Cl2 + 3 C -> 4 VOCl3 + 3 CO2 *Oxide replacement: *: rO42- + 2 Cl- + 4 H+ -> CrO2Cl2 + 4 H2O In addition, va ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triphosgene
Triphosgene (bis(trichloromethyl) carbonate (BTC) is a chemical compound with the formula OC(OCCl3)2. It is used as a solid substitute for phosgene, which is a gas. Triphosgene is stable up to 200 °C. Triphosgene is used in a variety of halogenation reactions. Preparation This compound is commercially available. It is prepared by exhaustive free radical chlorination of dimethyl carbonate: :CH3OCO2CH3 + 6 Cl2 → CCl3OCO2CCl3 + 6 HCl Triphosgene can be easily recrystallized from hot hexanes. Uses Triphosgene is used as a reagent in organic synthesis as a source of CO2+. It behaves like phosgene to which it cracks thermally: :OC(OCCl3)2 → 3 OCCl2 Alcohols are converted to carbonates. Primary and secondary amines are converted to ureas and isocyanates. Triphosgene has been used to synthesize organohalides. The use of triphosgene in these reactions provided a broader class of substrates that could be used for halogenation. Alkyl chlorides are synthesized via an SN2 reaction w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diphosgene
Diphosgene is an organic chemical compound with the formula ClCO2CCl3. This colorless liquid is a valuable reagent in the synthesis of organic compounds. Diphosgene is related to phosgene and has comparable toxicity, but is more conveniently handled because it is a liquid, whereas phosgene is a gas. Production and uses Diphosgene is prepared by radical chlorination of methyl chloroformate under UV light: :Cl-CO-OCH3 + 3 Cl2 —(hv)→ Cl-CO-OCCl3 + 3 HCl Another method is the radical chlorination of methyl formate: :H-CO-OCH3 + 4 Cl2 —(hv)→ Cl-CO-OCCl3 + 4 HCl Diphosgene converts to phosgene upon heating or upon catalysis with charcoal. It is thus useful for reactions traditionally relying on phosgene. For example, it convert amines into isocyanates, secondary amines into carbamoyl chlorides, carboxylic acids into acid chlorides, and formamides into isocyanides. Diphosgene serves as a source of two equivalents of phosgene: :2 RNH2 + ClCO2CCl3 → 2 RNCO + 4 HCl W ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxalyl Chloride
Oxalyl chloride is an organic chemical compound with the formula (COCl)2. This colorless, sharp-smelling liquid, the diacyl chloride of oxalic acid, is a useful reagent in organic synthesis. Preparation Oxalyl chloride was first prepared in 1892 by the French chemist Adrien Fauconnier, who reacted diethyl oxalate with phosphorus pentachloride. It can also be prepared by treating oxalic acid with phosphorus pentachloride. Oxalyl chloride is produced commercially from ethylene carbonate. Photochlorination gives the tetrachloride, which is subsequently degraded: :C2H4O2CO + 4 Cl2 → C2Cl4O2CO + 4 HCl :C2Cl4O2CO → C2O2Cl2 + COCl2 Reactions Oxalyl chloride reacts with water giving off gaseous products only: hydrogen chloride (HCl), carbon dioxide (CO2), and carbon monoxide (CO). : In this, it is quite different from other acyl chlorides which hydrolyze with formation of hydrogen chloride and the original carboxylic acid. Applications in organic synthesis Oxidation of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxalyl Fluoride
Oxalyl fluoride is the organofluorine compound with the formula (COF)2. It is a fluorinated derivative of oxalic acid. This colorless liquid is prepared by reaction of sodium fluoride with oxalyl chloride. Oxalyl fluoride is being investigated for use in etching as a replacement for compounds which have the liability of high global warming potential. See also * Oxalyl chloride * Oxalyl bromide * Dioxane tetraketone * Oxalyl The oxalyl cation, also known as ''oxalic'', has the chemical formula 2O2sup>2+. It is the cation derived from oxalic acid. Chemical compounds containing the oxalyl cation include: Related compounds/ions * Oxalic acid, C2O4H2 *The oxalate ani ... References Acyl fluorides Inorganic carbon compounds Carbon oxohalides {{Organohalide-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbonyl Bromide
Carbonyl bromide, also known as bromophosgene by analogy to phosgene, is an organic chemical compound. It is a carbon oxohalide. Carbonyl bromide is a decomposition product of halon compounds used in fire extinguishers. Reactions Carbonyl bromide is formed when carbon tetrabromide is melted and concentrated sulfuric acid is added. In contrast to phosgene, carbonyl bromide cannot be produced efficiently from carbon monoxide and bromine. A complete conversion is not possible due to thermodynamic reasons. Additionally, the reaction :CO + Br2 ⇌ COBr2 processes slowly at room temperature. Increasing temperature, in order to increase the reaction rate, results in a further shift of the chemical equilibrium towards the educts (since ΔRH < 0 and ΔRS < 0). On the other hand, carbonyl bromide slowly decomposes to carbon monoxide and elemental bromine even at low temperatures. It is also sensitive to |
Phosgene
Phosgene is the organic chemical compound with the formula COCl2. It is a toxic, colorless gas; in low concentrations, its musty odor resembles that of freshly cut hay or grass. Phosgene is a valued and important industrial building block, especially for the production of precursors of polyurethanes and polycarbonate plastics. Phosgene is extremely poisonous and was used as a chemical weapon during World War I, where it was responsible for 85,000 deaths. It was a highly potent pulmonary irritant and quickly filled enemy trenches due to it being a heavy gas. It is classified as a Schedule 3 substance under the Chemical Weapons Convention. In addition to its industrial production, small amounts occur from the breakdown and the combustion of organochlorine compounds, such as chloroform. Structure and basic properties Phosgene is a planar molecule as predicted by VSEPR theory. The C=O distance is 1.18 Å, the C−Cl distance is 1.74 Å and the Cl−C−Cl angle is 111 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbonyl Fluoride
Carbonyl fluoride is a chemical compound with the formula COF2. It is a carbon oxohalide. This gas, like its analog phosgene, is colourless and highly toxic. The molecule is planar with ''C''2v symmetry, bond lengths of 1.174 Å (C=O) and 1.312 Å (C–F), and an F–C–F bond angle of 108.0°. Preparation and properties Carbonyl fluoride is usually produced as a decomposition product of fluorinated hydrocarbons in the thermal decomposition thereof, for example from trifluoromethanol or tetrafluoromethane in the presence of water: : + → + 2 Carbonyl fluoride can also be prepared by reaction of phosgene with hydrogen fluoride and the oxidation of carbon monoxide, although the latter tends to result in over-oxidation to carbon tetrafluoride. The oxidation of carbon monoxide with silver difluoride is convenient: : + 2 → + 2 Carbonyl fluoride is unstable in the presence of water, hydrolyzing to carbon dioxide and hydrogen fluoride: : + → + 2 Safety Carbonyl fluor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dehydration Reaction
In chemistry, a dehydration reaction is a chemical reaction that involves the loss of water from the reacting molecule or ion. Dehydration reactions are common processes, the reverse of a hydration reaction. Dehydration reactions in organic chemistry Esterification The classic example of a dehydration reaction is the Fischer esterification, which involves treating a carboxylic acid with an alcohol to give an ester :RCO2H + R′OH RCO2R′ + H2O Often such reactions require the presence of a dehydrating agent, i.e. a substance that reacts with water. Etherification Two monosaccharides, such as glucose and fructose, can be joined together (to form saccharose) using dehydration synthesis. The new molecule, consisting of two monosaccharides, is called a disaccharide. Nitrile formation Nitriles are often prepared by dehydration of primary amides. :RC(O)NH2 → RCN + H2O Ketene formation Ketene is produced by heating acetic acid and trapping the product: :CH3CO2H → CH2=C= ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
