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Trichloroethylene (TCE) is a halocarbon with the formula C 2 HCl 3, commonly used as an industrial metal degreasing solvent. It is a clear, colourless, non-flammable, volatile liquid with a chloroform-like pleasant mild smell [3] and sweet taste. [9] Its IUPAC name is trichloroethene. Trichloroethylene has been sold under a variety of trade names.
The Evelyn effect is defined as the phenomena in which the product ratios in a chemical reaction change as the reaction proceeds. This phenomenon contradicts the fundamental principle in organic chemistry by reactions always go by the lowest energy pathway. The favored product should remain so throughout a reaction run at constant conditions.
Figure 6:Reaction Coordinate Diagrams showing reactions with 0, 1 and 2 intermediates: The double-headed arrow shows the first, second and third step in each reaction coordinate diagram. In all three of these reactions the first step is the slow step because the activation energy from the reactants to the transition state is the highest.
Initiation: The reaction is started by a free-radical source which may be a decomposing radical initiator such as AIBN. In the example in Figure 5, the initiator decomposes to form two fragments (I•) which react with a single monomer molecule to yield a propagating (i.e. growing) polymeric radical of length 1, denoted P 1 •.
For example, the industrial production of chloroethane proceeds by the reaction of ethylene with HCl: [citation needed] 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.
The Peterson olefination (also called the Peterson reaction) is the chemical reaction of α-silyl carbanions (1 in diagram below) with ketones (or aldehydes) to form a β-hydroxysilane (2) which eliminates to form alkenes (3).
1,1,1-Trichloroethane is an excellent solvent for many organic compounds and also one of the least toxic of the chlorinated hydrocarbons.It is generally considered non-polar, but owing to the good polarizability of the chlorine atoms, it is a superior solvent for organic compounds that do not dissolve well in hydrocarbons such as hexane.
Cascade reactions are often key steps in the efficient total synthesis of complex natural products. The key step in Heathcock's synthesis of dihydroprotodaphniphylline features a highly efficient cascade involving two aldehyde/amine condensations, a Prins-like cyclization, and a 1,5-hydride transfer to afford a pentacyclic structure from an acyclic starting material.