Decomposition Of Carbon Tetrachloride Research Articles

The surface and tribological chemistry of carbon tetrachloride on iron

The thermal decomposition of carbon tetrachloride on clean iron was studied in ultrahigh vacuum using molecular beam strategies, where it is found that carbon tetrachloride thermally decomposes on the surface to deposit iron and carbon with exactly identical kinetics as found at high pressures. No gas‐phase products are detected and the activation energy for the reaction (14.2 ± 0.5 kcal/mol) is in good agreement with the value measured at high pressures. Little carbon is detected on the surface using Auger spectroscopy following reaction and it is found that this diffuses into the surface much faster when formed from CCl4 than from CH2Cl2. This effect is ascribed to the effect of co‐adsorbed chlorine on the adsorbed carbon, which is proposed to decrease the activation energy for diffusion into the bulk of the sample. This effect explains the increased tendency for carbon tetrachloride to form carbides under extreme‐pressure tribological conditions.

Kinetics of carbon tetrachloride decomposition during the metalorganic vapor-phase epitaxy of gallium arsenide and indium arsenide

Carbon tetrachloride is used to dope gallium arsenide and indium–gallium arsenide films with carbon during metalorganic vapor-phase epitaxy (MOVPE). In this study, the decomposition kinetics of CCl 4 and of the other precursors (triethylgallium, trimethylindium and tertiarybutylarsine) were determined by monitoring the reactor feed and effluent gases with on-line infrared and mass spectroscopies. As the CCl 4 partial pressure was increased from 1×10 −4 to 3×10 −3 atm, the GaAs growth rate decreased and eventually fell to zero. Most of the reduction in growth rate (80 to 95%) was due to a surface reaction between adsorbed gallium and chlorine to produce volatile GaCl. The etching of the GaAs film by adsorbed chlorine to produce GaCl 3 accounted for the remainder of the growth rate reduction. The latter reaction was insignificant below a threshold CCl 4 partial pressure of ∼1.5×10 −3 atm at 450°C and ∼8.0×10 −4 atm at 550°C. A comparison of GaAs and InAs MOVPE revealed that the reaction of CCl 4 with indium to form volatile metal chlorides was nearly 10 times faster than the equivalent reactions with gallium.

Surface Chemistry of Chlorinated Hydrocarbon Lubricant Additives–-Part II: Modeling the Tribological Interface

In Part I (1), the concept of “Type I” antiseizure behavior for chlorinated hydrocarbons in extreme-pressure (EP) lubrication of ferrous metals was introduced; interfacial temperature measurements and surface analyses revealed that a solid lubricating layer consisting of ferrous chloride (FeCl2) and carbon prevents seizure and acts as a solid lubricant at less than ˜1000 K. In this paper, careful measurement of the film growth and removal rates successfully rationalizes this tribological behavior. Thermodynamic calculations also show that iron carbides are favored at higher decomposition temperatures. Analysis of films formed from the thermal decomposition of carbon tetrachloride (CCl4) and chloroform (CHCl3) at ˜1000 K using Mössbauer spectroscopy demonstrates that iron carbide is indeed formed in this case; tribological measurements also confirm this material as critical antiseizure material at high loads in “Type II” tribological behavior for chlorinated hydrocarbons with ferrous metals.

Mechanism of doping gallium arsenide with carbon tetrachloride during organometallic vapor-phase epitaxy

The rates of decomposition of carbon tetrachloride (CCl4), triethylgallium (TEGa), and tertiarybutylarsine (TBAs), and the rate of GaAs film growth, were measured as a function of the process conditions during organometallic vapor phase epitaxy. In addition, the reaction of CCl4 with the GaAs(001) surface was monitored in ultrahigh vacuum using infrared spectroscopy, temperature-programmed desorption, and scanning tunneling microscopy. These experiments have revealed that CCl4 adsorbs onto Ga sites, and decomposes by transferring chlorine ligands to other Ga atoms on the surface. Chlorine and gallium desorb from the surface as GaCl, while the carbon incorporates into the lattice. Triethylgallium is consumed by two competing reactions: GaAs film growth and GaCl etching. Depending on the V/III and IV/III ratios and temperature, the etch rate can be high enough to prevent any GaAs deposition.

Evaluation of the reaction rate constants for chlorinated ethylene and ethane decomposition in attachment-dominated atmospheric pressure dry-air plasmas

Pseudo-first-order reaction rate constants for the decomposition of carbon tetrachloride, trichloroethane, trichlorethylene, dichloroethane, dichloroethene, ethyl chloride and vinyl chloride were determined experimentally in an electron beam generated plasma reactor. The chlorinated ethylenes and ethanes were decomposed in a dry-air based attachment-dominated plasma. The experimental results agree well a simple, steady-state calculation used to predict the active species concentrations in the plasma and the overall pseudo-first-order reaction rate constants. Dissociative electron attachment is the dominant mechanism of decomposition of the chlorinated molecules, though oxygen radical reactions play a role as well.

Decomposition of Carbon Tetrachloride by a Packed Bed Plasma Reactor

AbstractIn search of a technology capable of controlling atmospheric pollutants, like volatile organic compounds (VOCs) in low concentrations, this paper is concerned with the empirical modeling of a ferroelectric plasma packed-bed reactor at ambient temperature and pressure. The empirical model gives information about the decomposition efficiency of the process as a function of the reactor operating variables. The volatile organic compound selected is Carbon Tetrachloride balanced with air in the concentration-range of 150 to 600 ppm and flow-range of 175 to 325 ml/min. Regarding the decomposition efficiency as the objective function, this modeling provides valuable information about the optimal operating conditions.

Tryptophan reaction with free radicals arisen from carbon tetrachloride in a model system. A mass spectrometric study.

The interaction between free radicals derived from the thermal decomposition of carbon tetrachloride and N-acetyl-d, l-tryptophan ethyl ester (TRPAE) under anaerobic and aerobic conditions was studied. The structure of the reaction products formed was deciphered by the GC/MS analysis of their trimethylsilyl derivatives. Under anaerobic conditions no formation of reaction products was detected. Under aerobic conditions the following products were identified: 1. A chloro hydroxy unsaturated adduct of TRPAE (2 isomers). 2. A dichloro hydroxy unsaturated adduct of TRPAE. 3. 12 products which are different pyrrolo[2,3-b]indol derivatives. Some of the products appeared to have an hydroxyl group as a substituent, all of them contained chlorine and only one contained carbon from CCl4. Interestingly, the formation of those adducts not containing CCl3 would be missed during the regular procedures toxicologists use to determine the so-called 'covalent binding' employing (14)CCl4. Concerning the potential relevance of these findings, we hypothesize that if interactions similar to those here reported occurred at least in part during CCl4 poisoning, the resulting critical proteins containing tryptophan, e.g. membrane or other and enzymes containing the amino acid in their active center, might be impaired.

Structure and Growth Kinetics of Films Formed by the Thermal Decomposition of CCl4on Iron Surfaces

Carbon tetrachloride thermally decomposes on iron in the temperature range 500−700 K to form films that consist predominantly of iron chloride. Two growth regimes are found: (1) parabolic, where the film thickness (X) varies as a function of time as X2 ∼ t and where the growth rate is independent of pressure, and (2) a linear growth region (X ∼ t), where the growth kinetics are first order in CCl4 pressure. The kinetics are analyzed by a model which assumes that growth is controlled either by CCl4 thermally decomposing at the growing gas−film interface or by diffusion through the film. Analysis of the experimental data gives an activation energy for diffusion of 21.5 ± 0.3 kcal/mol and an activation energy for CCl4 decomposition of 18.3 ± 0.5 kcal/mol. In contrast to the behavior found for methylene chloride and chloroform, where small particles of carbon were identified in the film using Raman spectroscopy, no carbon particles are found in films formed from carbon tetrachloride decomposition below ∼700 K although carbon is found in the film using X-ray photoelectron spectroscopy. XPS results also suggest that, in addition to completely thermally decomposing to yield carbon and chlorine, a small portion of the CCl4 can react to form adsorbed CCl2 species.

Hydroxyproline reaction with free radicals generated during benzoyl peroxide catalytic decomposition of carbon tetrachloride Structure of reaction products formed

Benzoyl peroxide catalytic decomposition of carbon tetrachloride in a model system produces trichloromethyl and trichloromethylperoxyl free radicals. These radicals are also produced by CCl4 bioactivation in liver and are considered to be responsible for the deleterious effects of this hepatotoxin. In this study, it is attempted to learn about how the .CCl3 and CCl3O2. tend to react with hydroxyproline in a model system. Hydroxyproline was selected because of its role in collagen metabolism. During the interaction of both radicals with hydroxyproline a total of 16 reaction products were isolated and identified by gas chromatographic-mass spectrometric analysis. All of them were hydroxyproline analogs, no single one contained C from CCl4 and only three contained chlorine. Consequently, most adducts would be missed in experiments where formation of reaction products are studied by formation of(14)C or(36)Cl labeled adducts (e.g. covalent binding studies used by toxicologists). If similar hydroxyproline analog reaction products were observed during CCl4 intoxication it might be reasonably expected that they interfered with collagen metabolism and participate in cirrhogenic effects of CCl4 on the liver.

Electron Beam Atmospheric Pressure Cold Plasma Decomposition of Carbon Tetrachloride and Trichloroethylene

The cold plasma decomposition of carbon tetrachloride (CCl 4 ) and trichloroethylene (C 2 HCl 3 ) at dilute concentrations in dry and wet air of atmospheric pressure was investigated. The cold plasma was generated in a tunable plasma reactor, where the electron concentration is controlled by an electron beam and the average electron energy is controlled by a superimposed sub-breakdown electric field. The energy expense for decomposition, i.e., the electron beam energy per molecule decomposed, as well as the intermediate and final decomposition products were determined. Moreover, likely reaction mechanisms for the decomposition of CCl 4 and C 2 HCl 3 are presented. These mechanisms are based on bimolecular dissociative electron attachment for both CCl 4 and C 2 -HCl 3 and additionally a chlorine chain reaction for C 2 HCl 3 . The present work provides a reference for the development of an advanced oxidation process on the basis of a tunable plasma reactor. Such a process would be especially suitable for the treatment of air contaminated with chemical compounds that dissociatively attach electrons.

Decomposition of CCl4 on CaO

Transmission infrared spectroscopy was used to monitor CCl x (a) intermediate surface species formed during the decomposition of CCl 4 on high surface area calcium oxide. Carbon tetrachloride was adsorbed on calcium oxide at 113 K During CCl 4 desorption, additional infrared bands at 801, 787, 775, 765, and 751 cm -1 were observed in the temperature range 110-250 K. These bands, which disappeared in the temperature range 150-250 K, were attributed to the formation and depletion of CCl x (a) species as C-Cl bonds are broken and Ca-Cl bonds are formed on the CaO surface. Carbon tetrachloride ( 13 C labeled) was employed to prove that the infrared bands of the surface intermediates were due to C-Cl vibrational modes. To compare carbon tetrachloride decomposition on different types of calcium oxides, both autoclave prepared (nanoscale particles) and conventionally prepared CaO were investigated.

Tyrosine attack by free radicals derived from catalytic decomposition of carbon tetrachloride

The interaction between free radicals derived from the catalytic decomposition of carbon tetrachloride and tyrosine (the N-acetyl tyrosine ethyl ester, ATEE) under anaerobic and aerobic conditions was studied. The structure of the reaction products formed was desciphered by the GLC/MS analysis of their trimethylsilyl derivatives. Under anaerobic conditions the formation of the following products was found: (1) an unsaturated derivative of the amino acid; (2) the trimethylsilyl derivative of N-acetyl chloro tyrosine ethyl ester; (3) a hydroxyl adduct of ATEE ; (4) an ATEE adduct having a chlorine and a CCl 3 group in the molecule (it is suggested that CCl 3 is attached to the benzyl carbon and the chlorine located in the benzene ring); (5) an ATEE adduct having only a CCl 3 group tentatively assigned to be located on the benzyl carbon; and (6) and (7) were found to be two isomers of an ATEE having one CCl 3 on the aromatic ring. Under aerobic conditions the following reaction products were identified: Two products which were similar to those numbered (1) and (2) and formed anaerobically; (8) and (11) two isomeric dichlorinated adducts of ATEE; (9) and (10) two isomeric dichlorinated monohydroxylated derivatives of ATEE. Concerning the potential relevance of these findings, we consider that if similar interactions to those here reported occurred during CCl 4 poisoning, the activity of enzymes having tyrosine in their active center might result in impairment. Further, enzymes operating on tyrosine moieties in proteins might be perturbed in their action if tyrosine groups were attacked by the free radicals arising from catalytic decomposition of CCl 4 evidenced here.

Two-laser-sensitized decomposition of carbon tetrachloride: photoacid generation

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTTwo-laser-sensitized decomposition of carbon tetrachloride: photoacid generationT. Gannon and W. G. McGimpseyCite this: J. Org. Chem. 1993, 58, 21, 5639–5642Publication Date (Print):October 1, 1993Publication History Published online1 May 2002Published inissue 1 October 1993https://doi.org/10.1021/jo00073a022RIGHTS & PERMISSIONSArticle Views83Altmetric-Citations20LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (491 KB) Get e-Alerts Get e-Alerts

Transformations of halogenated organic compounds under denitrification conditions.

Trihalomethanes, carbon tetrachloride, 1,1,1-trichloroethane, 1,2-dibromoethane, chlorinated benzenes, ethylbenzene, and naphthalene at concentrations commonly found in surface and groundwater were incubated under anoxic conditions to study their transformability in the presence of denitrifying bacteria. None of the aromatic compounds showed significant utilization relative to sterile controls at initial concentrations from 41 to 114 micrograms/liter after 11 weeks of incubation. Of the halogenated aliphatic compounds studied, transformations of carbon tetrachloride and brominated trihalomethanes were observed after 8 weeks in batch denitrification cultures. Carbon from the decomposition of carbon tetrachloride was both assimilated into cell material and mineralized to carbon dioxide. How this was possible remains unexplained, since carbon tetrachloride is transformed to CO2 by hydrolysis and not by oxidation-reduction. Chloroform was detected in bacterial cultures with carbon tetrachloride initially present, indicating that reductive dechlorination had occurred in addition to hydrolysis. The data suggest that transformations of certain halogenated aliphatic compounds are likely to occur under denitrification conditions in the environment.

ChemInform Abstract: PHOTO‐ETHOXYCARBONYLATION OF ANISOLE, DIMETHYLANILINE AND THIOPHENE IN CARBON TETRACHLORIDE‐ETHANOL SOLUTIONS

AbstractDie Bildung der Äthoxycarbonylderivate erfolgt hauptsächlich über die Bildung eines CT‐Komplexes aus z.B. Anisol und Tetrachlorkohlenstoff.

Photo-ethoxycarbonylation of Anisole, Dimethylaniline and Thiophene in Carbon Tetrachloride–Ethanol Solutions

Abstract UV-Irradiation of anisole, dimethylaniline and thiophene with carbon tetrachloride in ethanol produced ethoxycarbonylated compounds. In general, this photo-ethoxycarbonylation proceeds effectively when a charge transfer complex between aromatic compound and carbon tetrachloride is excited. Attack of tnchloromethyl radicals formed by the sensitized decomposition of carbon tetrachloride also occurs in parallel with the charge transfer mechanism.

The pulmonary response of rats exposed to the decomposition products of carbon tetrachloride vapors at its industrial threshold limit concentration.

This study was conducted to determine whether or not carbon tetrachloride decomposition products would produce a degree of toxic effect more than that predicted from the chemical assessment of phosgene, chlorine, chlorine dioxide, and hydrogen chloride, owing to the potentiation of action of these components or the presence of unidentified, highly toxic compounds. It was shown that chlorine, chlorine dioxide, and hydrogen chloride did contribute to respiratory impairment as well as phosgene. No potentiating effect due to these chemicals was observed. Unidentified “other chloride” compounds are similar to hydrogen chloride with respect to animal response. It is concluded that the health hazards of a mixture of carbon tetrachloride decomposition products may best be assessed on the basis of the additive effect of these chemicals.

Thermal decomposition of carbon tetrachloride vapors at its industrial threshold limit concentration.

The products from the thermal decomposition of carbon tetrachloride at its industrial threshold limit concentration of 10 ppm may be potentially hazardous, and possibly lethal, under some conditions. Phosgene, chlorine, chlorine dioxide, and hydrogen chloride were measured. Carbon tetrachloride vapors in contact with iron and glass surfaces decomposed at lower temperatures than when in contact with glass alone. A clean iron surface accelerated the decomposition of carbon tetrachloride and phosgene and the formation of chlorine; a “corroded” iron surface further accelerated these reactions, with less decomposition of phosgene. Humidity had very little effect on phosgene decomposition but significantly reduced the concentrations of chlorine and chlorine dioxide. Open flames, depending upon the degree of contact, may cause complete decomposition to hydrogen chloride. It is necessary to measure all of the decomposition products and to consider that their toxic effects may be additive.

Decomposition of carbon tetrachloride in the field of ultrasonic waves: J. Chem., 37, No. 1, p. 13 (1963

Decomposition of carbon tetrachloride in the field of ultrasonic waves: J. Chem., 37, No. 1, p. 13 (1963

Decomposition of Organic Halogen Compounds by Ultrasonic Waves. Pt. I-Mechanism of the Decomposition of Carbon Tetrachloride in Presence of Water

Article Decomposition of Organic Halogen Compounds by Ultrasonic Waves. Pt. I-Mechanism of the Decomposition of Carbon Tetrachloride in Presence of Water was published on December 1, 1957 in the journal Zeitschrift für Physikalische Chemie (volume 208O, issue 1).