Chlorine with ethene

The following is a possible simplified mechanism for the reaction of chlorine with ethene C2H4. 

One of the products of the reaction of sulfur with chlorine is disulfur dichloride, S2C12, a yellow liquid with a nauseating smell it is used for the vulcanization of rubber. When disulfur dichloride reacts with more chlorine in the presence of iron(III) chloride as a catalyst, the foul-smelling red liquid sulfur dichloride, SC12, is produced. Sulfur dichloride reacts with ethene to give mustard gas (16), which has been used in chemical warfare. Mustard gas causes blisters, discharges from the nose, and vomiting it also destroys the cornea of the eye. All in all, it is easy to see why ancient civilizations associated sulfur with the underworld. 

Classify each of the following reactions as addition or substitution and write its chemical equation (a) chlorine reacts with methane when exposed to light (b) bromine reacts with ethene in the absence of light. 

The entropy change AS0 for the formation of chloroethane by chlorination of ethane is +0.5 e.u., and for the formation of chloroethane by combination of hydrogen chloride with ethene AS0 is —31 e.u. Explain. 

The most economical commercial preparation is high-temperature chlorination of ethene. A useful modification of this process uses hydrogen chloride in place of chlorine. An oxidizing agent is required to raise the oxidation state of chlorine in HC1 to that of Cl2 molecular oxygen is used for this purpose along with cupric salts as catalysts. 

Dowideit P, VonSonntag C. Reaction of ozone with ethene and its methyl-and chlorine-substituted derivatives in aqueous solution. Environ Sci Technol 1998 32 1112-1119. 

Substitution of hydrogen, in an alkene, by fluorine leads to increased reactivity for a number of processes for example, with tetrafluoroethene, heats of addition of chlorine, hydrogenation and polymerisation are 58.5, 66.9 and 71.1kJmol greater, respectively, than for the analogous reactions with ethene [3, 29]. These observations could be attributed either to an increase in the carbon-fluorine bond strength upon changing the hybridisation of the carbon atoms bonded to fluorine [30] or to ir-bond destabilisation by fluorine [31]. 

The most important use of chlorine is to make other chemicals. For example, chlorine can be combined with ethene, or ethylene, gas (C2H2), to make ethylene dichloride (C2H2CI2) ... 

The reaction between ethyne and phosgene has also been studied under photochemical conditions (>220 nm) [2185a]. As in the analogous reaction with ethene (see Section 10.1.2), the phosgene merely acts as a convenient source of chlorine radicals the principal products were CO, CHj=CHCl, 1-chloro-l, 3-butadiene, benzene and polymer trace amounts of HC Cl and CgHjCl were also detected [2185a]. 

Chloroethene, compd. with ethene. See Polyethylene, chlorinated Chloroethene homopolymer. See Polyvinyl chloride... 

Synonyms Chlorinated polyethylene Chloroethene, compd. with ethene CPE Classification Olefin Properties Wh. gran. dens. 1.220 Toxicology May be harmful by inh., ing., or skin absorption may cause skin/eye irritation Precaution May dec. under fire conditions to form flamm./explosive mixts. in air Hazardous Decomp. Prods. CO, CO2, hydrogen chloride gas Uses Infoodpkg. 

Alkenes react rapidly with bromine and chlorine in nonnucleophilic solvents to form vicinal dihalides. An example is the addition of chlorine to ethene. 

After his trip to Europe with Davy, Faraday resumed work at the Royal Institution. Initially he assisted Davy, but he gradually increased in confidence and independence. Since it was now known that chlorine would support combustion, Faraday was surprised that carbon, one of the most combustible elements, formed no chlorine compounds. In 1820 he found that when he reacted the compound known as oil of the Dutch chemists (1,2-dichloroethane, prepared from the reaction of chlorine with olefiant gas, i.e. ethene) with chlorine in sunlight, he obtained per chloride of carbon (C2CI5). This was the first substitution reaction, and reactions of this type were later to present a serious challenge to the dualistic theory. By passing perchloride of carbon through a red-hot tube, Faraday obtained protochloride of carbon (C2CI4). 

Scheme 6.53. The reaction of chlorine (CI2) with ethene (ethylene, H2C=CH2) to produce 1,2-dichloroethane (CIH2CCH2CI) followed by elimination of hydrogen chloride (HCl) from a different rotational conformer in either a iy -coplanar (or cis or suprafacial) or an anti-coplanar (or trans or antarafacial) sense to produce chloroethene [C1(H)C=CH2].

Industrially it is produced by the chlorination of ethene, either by the direct chlorination process using chlorine or by the oxychlorination with hydrogen chloride as... 

Wallington, T.J., J.M. Andino, I.M. Lorkovic, E.W Kaiser, and G. Marston (1990c), Pressure dependence of the reaction of chlorine atoms with ethene and acetylene in air at 295 K,... 

CH2C1 CH2C1. Colourless liquid with an odour like that of chloroform b.p. 84 C. It is an excellent solvent for fats and waxes. Was first known as oil of Dutch chemists . Manufactured by the vapour- or liquid-phase reaction of ethene and chlorine in the presence of a catalyst. It reacts with anhydrous ethano-ales to give ethylene glycol diethanoate and with ammonia to give elhylenediamine, these reactions being employed for the manufacture of these chemicals. It burns only with difficulty and is not decomposed by boiling water. 

Attention is drawn to the dechlorination by anaerobic bacteria of both chlorinated ethenes and chlorophenolic compounds that serve as electron acceptors with electron donors including formate, pyruvate, and acetate. This is termed dehalorespiration and is important in the degradation of a range of halogenated compounds under anaerobic conditions, and is discussed further in Chapter 3, Part 2 and Chapter 7, Part 3. 

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