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The chloroform molecule can be viewed as a methane molecule with three hydrogen atoms replaced with three chlorine atoms, leaving a single hydrogen atom. The name "chloroform" is a portmanteau of terchloride (tertiary chloride, a trichloride) and formyle, an obsolete name for the methylylidene radical (CH) derived from formic acid. [citation ...
H 2 C=CH 2 + HCl → CH 3 CH 2 Cl. In oxychlorination, hydrogen chloride instead of the more expensive chlorine is used for the same purpose: CH 2 =CH 2 + 2 HCl + 1 ⁄ 2 O 2 → ClCH 2 CH 2 Cl + H 2 O. Secondary and tertiary alcohols react with hydrogen chloride to give the corresponding chlorides.
In 1835, the French chemist Auguste Laurent recognised chloroform as CCl 2 • HCl (then written as C 8 Cl 8 • H 4 Cl 4) [a] in his paper on analysing some organohalides. Laurent also predicted a compound seemingly consisting of 2 parts dichlorocarbene which he named Chlorétherose (possibly Tetrachloroethylene, which was not known to exist at the time.) [8]
In chemistry, the haloform reaction (also referred to as the Lieben haloform reaction) is a chemical reaction in which a haloform (CHX 3, where X is a halogen) is produced by the exhaustive halogenation of an acetyl group (R−C(=O)CH 3, where R can be either a hydrogen atom, an alkyl or an aryl group), in the presence of a base.
Other products such as CH 2 Cl 2 may also form. Chain termination Two free radicals (chlorine and chlorine, chlorine and methyl, or methyl and methyl) combine: Methane chlorination: termination The last possibility generates in an impurity in the final mixture (notably, an organic molecule with a longer carbon chain than the reactants).
A chloroform-degrading reductive dehalogenase enzyme has been reported in a Dehalobacter member. The chloroform reductive dehalogenase, termed TmrA, was found to be transcriptional up-regulated in response to chloroform respiration [12] and the enzyme can be obtained both in native [13] and recombinant forms. [14]
In the simplest sense this consists of an aqueous hydroxide solution and an organic phase containing the chloroform. Therefore, the two reagents are separated and must be brought together for the reaction to take place. This can be achieved by rapid mixing, phase-transfer catalysts, or an emulsifying agent such as 1,4-dioxane as solvent.
The mechanism for addition of a carbene to an alkene is a concerted [2+1] cycloaddition (see figure). Carbenes derived from chloroform or bromoform can be used to add CX 2 to an alkene to give a dihalocyclopropane, while the Simmons–Smith reagent adds CH 2. [10]