Ethyl chloride decomposition

This work did not take into consideration the heavy isotope effects, and the conclusion reached by Christie and coworkers38 from 35C1/37C1 isotope effects in the ethyl chloride decomposition disagreed with the activated complex model depicted above. 

As a final point, consider the observed behavior of the major product yields with increasing ethyl chloride decomposition (Figure 7). The dichlorobutane yield is essentially constant with an increase in the absorbed radiation dose, while the ethane yield rises sharply and the ethylene-acetylene product is substantially reduced. These observations suggest the occurrence of additional reaction processes other than those already suggested. Also, the fact that the ethane increase is not matched by the ethylene decrease indicates that these two phenomena are not necessarily coupled. The most likely explanation is that ethylene is attacked by Cl atoms,... 

Other acetyl chloride preparations include the reaction of acetic acid and chlorinated ethylenes in the presence of ferric chloride [7705-08-0] (29) a combination of ben2yl chloride [100-44-7] and acetic acid at 85% yield (30) conversion of ethyUdene dichloride, in 91% yield (31) and decomposition of ethyl acetate [141-78-6] by the action of phosgene [75-44-5] producing also ethyl chloride [75-00-3] (32). The expense of raw material and capital cost of plant probably make this last route prohibitive. Chlorination of acetic acid to monochloroacetic acid [79-11-8] also generates acetyl chloride as a by-product (33). Because acetyl chloride is cosdy to recover, it is usually recycled to be converted into monochloroacetic acid. A salvage method in which the mixture of HCl and acetyl chloride is scmbbed with H2SO4 to form acetyl sulfate has been patented (33). 

Ethyl chloride can be dehydrochlorinated to ethylene using alcohoHc potash. Condensation of alcohol with ethyl chloride in this reaction also produces some diethyl ether. Heating to 625°C and subsequent contact with calcium oxide and water at 400—450°C gives ethyl alcohol as the chief product of decomposition. Ethyl chloride yields butane, ethylene, water, and a soHd of unknown composition when heated with metallic magnesium for about six hours in a sealed tube. Ethyl chloride forms regular crystals of a hydrate with water at 0°C (5). Dry ethyl chloride can be used in contact with most common metals in the absence of air up to 200°C. Its oxidation and hydrolysis are slow at ordinary temperatures. Ethyl chloride yields ethyl alcohol, acetaldehyde, and some ethylene in the presence of steam with various catalysts, eg, titanium dioxide and barium chloride. 

In order to obtain compounds with Ti-O-P and Zr-O-P units, the hexaethoxy-derivative, NsPaCOEOg, was treated with titanium and zirconium tetrachlorides. In each case, hygroscopic solids of the type NaPaCOEOiOaMCU (M = Ti or Zr) and ethyl chloride were obtained. The degree of polymerization of these solids was 1.6—1.8, and on the basis of their i.r. and n.m.r. spectra, two alternative structures, (46) and (47), were proposed. In an alternative route to the same type of compound, N3P3CI6 was treated with tetra-n-butoxytitanium in o-xylene. Butyl chloride was liberated and a solid was obtained which has been assigned the structure (48). Its thermal decomposition was studied by differential thermal analysis. 

Propane was selected as solvent for the isobutene for experiments down to -145° the aluminium chloride was dissolved in ethyl chloride, for the work at lower temperatures a mixture of ethyl chloride and vinyl chloride was used. Although these catalyst solutions were made up at -78° they were yellow, and as stated above, they probably contained some hydrogen chloride and other catalytically active decomposition products. The polymerisations were carried out by running the cooled catalyst solution into the monomer solution. Polymer was formed, and came out of solution, almost immediately, and the reaction was very fast even at the lowest temperature (-185°) and lowest monomer concentration (0.6 mole/1). After the reaction was over, propanol at the reaction temperature was added to the reaction mixture to deactivate the catalyst. 

The gaseous products formed on thermal decomposition of ethylene-platinous chloride are ethylene, hydrogen chloride, vinyl chloride, ethyl chloride, ethylene dichloride and ethylidine dichloride. The half life for the decomposition at 130° is 4.5 days, at 172° it is 1.7 hours 98). The hydrolysis of Zeisc s salt K[PtCl3(C2H4)] by water and dilute acids has been studied ... 

As the inner salts are generally unstable and insoluble, they cannot be manipulated and their structures were therefore inferred from those of the more stable nitrogen analogues. The inner oxonium salt from boron fluoride, when examined at low temperatures, was found to contain a molecule of ether of crystallization which was held very tenaciously and was involved in the complex decomposition of the salt at higher temperatures. The salt from antimony pentachloride did not contain this molecule of ether and decomposed to ethyl chloride and a mixture of alkoxy antimony tetrachlorides. The stannic chloride decomposed in at least two ways,... 

Recently, Huybrechts and coworkers56 carried out a numerical integration for a hypothetical molecular and radical model for the HC1 elimination from ethyl chloride in the gas phase. The simulation data indicated that a radical chain process does not contribute to the decomposition rate. Only ethylene and hydrogen chloride are formed in the molecular decomposition. 

The homogeneous unimolecular decomposition of o-hydroxy-2-phenvlethyl chloride yielded mainly benzodihydrofuran, HC1 and much less o-hydroxystyrene. The rate was significantly higher than that of phenylethyl chloride and ethyl chloride (Table 28). According to the nature of the product formation and the kinetic data, the OH provided anchimeric assistance in the elimination process. The mechanism proposed is described in equations 87 and 88. 

Schwab has pointed out that the following relationship between the two parameters of the Arrhenius equation is frequently encountered. A decrease in the activation energy of a given reaction, for a series of catalysts, often does not increase the reaction rate to the extent calculated, because of a simultaneous decrease of the frequency factor. Cremer (106) confirmed this for the decomposition of ethyl chloride on various chloride catalysts. These findings will be discussed here with due regard to the relation between adsorption and elementary reaction rates dealt with in the preceding section. 

An isotope effect can also occur in the rate of a chemical reaction. Thus, isotopic substitution has a pronounced effect on the falling-oflf of the rate coefficient for the decomposition of ethyl chloride and also produces evidence for a four-centred... 

The reactions represented are the combination of hydrogen and chlorine, the decomposition of mercury cyanide, the hydrolysis of acetyl chloride, and the reaction of ethyl chloride with anamonia to form ethylamine and hydrogen chloride. The reagents are shown left and right the products are separated by the horizontal line and by a vertical line where necessary.—O.T.B.]... 

As in steam cracking, a large number of by-products is produced. Some of them result from the consecutive reactions of the chlorination of vinyl chloride and of its derivatives obtained by dehydrochlorination (tri-, tetra-, pentachloroethane, perchloro-ethane, di-, trichloroethylene. perchloroethyleneX and the others from the hydrochlorination of vinyl chloride il.l-dichloroethane), while others result from decomposition reactions (acetylene, cokei or conversion of impurities initially present (hydrocarbons such as ethylene, butadiene and benzene, chlorinated derivatives such as chloroprene, methyl and ethyl Chlorides, chloroform, carbon tetrachloride, eta, and hydrogen) ... 

No direct data for the decomposition of alkyl halides by clean, active metal surfaces seem to be available. Campbell and Kemball [11], in their study of the hydrogenolysis of ethyl chloride, cite evidence for the dehydrochlorination reaction... 

Table IV gives the relative product distribution from the vacuum ultraviolet photolysis of ethyl chloride at 40 mm. pressure using the 1236-A. krypton resonance line. Owing to the low intensity of emission from the resonance lamp, higher pressures were not used in the photolysis experiments in order to prevent the major portion of the reaction from occurring in the region of the window where surface interactions are likely. Therefore, to provide a basis for more direct comparison between the photolytic and radiolytic yields, the radiolysis of ethyl chloride was also examined at 40 mm. pressure. The relative yields from several experiments of the latter study are given in Table IV. The lowest conversion yields from the radiolysis at the lower pressure show a relative distribution which is in close agreement with the relative product distribution detected from the radiolysis at 357 mm. Therefore, there is no substantial pressure effect on the decomposition product yields in ethyl chloride over the range 40-357 mm.

The photolysis data provide important information relative to the modes of decomposition of excited ethyl chloride molecules. The fact that the photolysis yields show a larger excess of ethylene-acetylene... 

The proposed mechanism for photolytic decomposition of ethyl chloride predicts the product relation, 2[C4H8C12] + [C4H9C1] = [H2] radical + [C2H6] + [CH4] + [HC1]. Inserting the indicated concentrations from Table V into this equation gives 1.09 = 0.72 + [HC1]. Clearly, HC1 must be a substantial product, even though we were unable to estimate its concentration in our experiments, and presumably it would account for the remainder of the material balance. 

---