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Cas Database

67-66-3

67-66-3

Identification

  • Product Name:Chloroform

  • CAS Number: 67-66-3

  • EINECS:200-663-8

  • Molecular Weight:119.378

  • Molecular Formula: CHCl3

  • HS Code:2903.13 oral rat LD50: 910 mg/kg

  • Mol File:67-66-3.mol

Synonyms:Methyl trichloride;Freon 20;R 20 (refrigerant);Trichloormethaan;Methane trichloride;Cloroformio;Chloroforme;Triclorometano;NCI-C02686;Methenyl trichloride;Methane, trichloro-;Trichlormethan;Trichloroform;Trichloromethane;Methane,trichloro-;Formyl trichloride;Industrial Chloroform;Chloroform, Reagent;Chloroform, Spectrophotometric Grade;

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Safety information and MSDS view more

  • Pictogram(s):HarmfulXn, FlammableF, ToxicT

  • Hazard Codes: Xn:Harmful;

  • Signal Word:Danger

  • Hazard Statement:H302 Harmful if swallowedH315 Causes skin irritation H319 Causes serious eye irritation H331 Toxic if inhaled H351 Suspected of causing cancer H372 Causes damage to organs through prolonged or repeated exposure H361d

  • First-aid measures: General adviceConsult a physician. Show this safety data sheet to the doctor in attendance.If inhaled Fresh air, rest. Artificial respiration may be needed. Refer for medical attention. In case of skin contact Remove contaminated clothes. Rinse skin with plenty of water or shower. Refer for medical attention . In case of eye contact First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention. If swallowed Rinse mouth. Give one or two glasses of water to drink. Rest. Refer for medical attention . It is classified as moderately toxic. Probable oral lethal dose for humans is 0.5 to 5 g/kg (between 1 ounce and 1 pint) for a 150 lb. person. The mean lethal dose is probably near 1 fluid ounce (44 g). It is a human suspected carcinogen. Also, it is a central nervous system depressant and a gastrointestinal irritant. It has caused rapid death attributable to cardiac arrest and delayed death from liver and kidney damage. (EPA, 1998) Immediate first aid: Ensure that adequate decontamination has been carried out. If patient is not breathing, start artificial respiration, preferably with a demand-valve resuscitator, bag-valve-mask device, or pocket mask, as trained. Perform CPR as necessary. Immediately flush contaminated eyes with gently flowing water. Do not induce vomiting. If vomiting occurs, lean patient forward or place on left side (head-down position, if possible) to maintain an open airway and prevent aspiration. Keep patient quiet and maintain normal body temperature. Obtain medical attention. /Halogenated aliphatic hydrocarbons and related compounds/

  • Fire-fighting measures: Suitable extinguishing media Use water spray to keep fire-exposed containers cool. Extinguish fire using agent suitable for surrounding fire. Container may explode in the heat of fire. When heated it liberates phosgene, hydrogen chloride, chlorine and toxic and corrosive oxides of carbon and chlorine. Chloroform explodes when in contact with aluminum powder or magnesium powder or with alkali metals (e.g., lithium, sodium, and potassium) and dinitrogen tetroxide. It reacts vigorously with acetone in the presence of potassium hydroxide or calcium hydroxide. It is oxidized by strong oxidizers such as chromic acid forming phosgene and chlorine. It reacts vigorously with triisopropylphosphine. It develops acidity from prolonged exposure to air and light. (EPA, 1998) Wear self-contained breathing apparatus for firefighting if necessary.

  • Accidental release measures: Use personal protective equipment. Avoid dust formation. Avoid breathing vapours, mist or gas. Ensure adequate ventilation. Evacuate personnel to safe areas. Avoid breathing dust. For personal protection see section 8. Evacuate danger area! Consult an expert! Personal protection: complete protective clothing including self-contained breathing apparatus. Do NOT let this chemical enter the environment. Collect leaking and spilled liquid in sealable containers as far as possible. Absorb remaining liquid in sand or inert absorbent. Then store and dispose of according to local regulations. 1. Ventilate area of spill or leak. 2. Collect for reclamation or absorb in vermiculite, dry sand, earth, or a similar material.

  • Handling and storage: Avoid contact with skin and eyes. Avoid formation of dust and aerosols. Avoid exposure - obtain special instructions before use.Provide appropriate exhaust ventilation at places where dust is formed. For precautions see section 2.2. Separated from food and feedstuffs and incompatible materials. See Chemical Dangers. Ventilation along the floor.Keep in tightly closed containers; storage code: LI

  • Exposure controls/personal protection:Occupational Exposure limit valuesNIOSH considers chloroform to be a potential occupational carcinogen.Recommended Exposure Limit: 60 Min Short-Term Exposure Limit: 2 ppm (9.78 mg/cu m).Biological limit values Handle in accordance with good industrial hygiene and safety practice. Wash hands before breaks and at the end of workday. Eye/face protection Safety glasses with side-shields conforming to EN166. Use equipment for eye protection tested and approved under appropriate government standards such as NIOSH (US) or EN 166(EU). Skin protection Wear impervious clothing. The type of protective equipment must be selected according to the concentration and amount of the dangerous substance at the specific workplace. Handle with gloves. Gloves must be inspected prior to use. Use proper glove removal technique(without touching glove's outer surface) to avoid skin contact with this product. Dispose of contaminated gloves after use in accordance with applicable laws and good laboratory practices. Wash and dry hands. The selected protective gloves have to satisfy the specifications of EU Directive 89/686/EEC and the standard EN 374 derived from it. Respiratory protection Wear dust mask when handling large quantities. Thermal hazards

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Relevant articles and documentsAll total 284 Articles be found

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Teeple

, p. 536 (1904)

-

Treszcyanowicz,Bakowski

, (1948)

Gas-phase photooxidation of trichloroethylene on TiO2 and ZnO: Influence of trichloroethylene pressure, oxygen pressure, and the photocatalyst surface on the product distribution

Driessen,Goodman,Miller,Zaharias,Grassian

, p. 549 - 556 (1998)

Transmission Fourier transform infrared spectroscopy has been used to identify gas-phase and surface-bound products and intermediates formed during the gas-phase photooxidation of trichloroethylene (TCE) on TiO2 and ZnO. Several factors are found to influence the gas-phase product distribution for this reaction. On clean TiO2 and ZnO surfaces and at high TCE and O2 pressures, gas-phase CO, CO2, COCl2, CCl2HCOCl, CHCl3, C2HCl5, and HCl are produced, whereas at low TCE and O2 pressures, TCE is converted to gas-phase CO and CO2 only. In addition to TCE and O2 pressure, the product distribution of the photooxidation of TCE is strongly dependent upon the coverage of adsorbed species on the surface of the photocatalyst. It is shown here that the complete oxidation of adsorbed TCE can occur on clean photocatalytic surfaces whereas only partial oxidation of adsorbed TCE occurs on adsorbate-covered surfaces. The role of adsorbed surface products in TCE photooxidation is discussed.

Kinetics of the R + HBr ? RH + Br (R = CH2Br, CHBrCl or CCl3) equilibrium. Thermochemistry of the CH2Br and CHBrCl radicals

Seetula, Jorma A.

, p. 849 - 855 (2003)

The kinetics of the reaction of the CH2Br, CHBrCl or CCl3 radicals, R, with HBr have been investigated separately in a heatable tubular reactor coupled to a photoionization mass spectrometer. The CH2Br (or CHBrCl or CCl3) radical was produced homogeneously in the reactor by a pulsed 248 nm exciplex laser photolysis of CH2Br2 (or CHBr2Cl or CBrCl3). The decay of R was monitored as a function of HBr concentration under pseudo-first-order conditions to determine the rate constants as a function of temperature. The reactions were studied separately over a wide ranges of temperatures and in these temperature ranges the rate constants determined were fitted to an Arrhenius expression (error limits stated are 1σ + Student's t values, units in cm3 molecule-1 s-1): k(CH2Br + HBr) = (7.5 ± 0.9) × 10-13 exp[- (2.53 ± 0.13) kJ mol-1/RT], k(CHBrCl + HBr) = (4.9 ± 1.1) × 10-13 exp[-(8.2 ± 0.3) kJ mol-1/RT] and k(CCl3 + HBr) -15 at 787 K. The kinetics of the reverse reactions, Br + R′H → HBr + R′ (R′ = CH2Br or CHBrCl), were taken from the literature and also calculated by ab initio methods at the MP2(fc)/6-31G(d,p)//MP2(fc)/6-31G(d,p) level of theory in conjunction with the thermodynamic transition state theory to calculate the entropy and the enthalpy of formation values of the radicals studied. The thermodynamic values were obtained at 298 K using a second-law method. The results for entropy values are as follows (units in J K-1 mol-1): 263 ± 7 (CH2Br) and 294 ± 6 (CHBrCl). The results for enthalpy of formation values at 298 K are (in kJ mol-1): 171.1 ± 2.7 (CH2Br) and 143 ± 6 (CHBrCl). The C-H bond strength of analogous halomethanes are (in kJ mol-1): 427.2 ± 2.4 (CH3Br) and 406.0 ± 2.4 (CH2BrCl). Thermodynamic properties of the CH2Br radical were calculated by statistical thermodynamic methods over the temperature range 100-1500 K.

KINETICS OF THE GAS-PHASE PHOTOCHLORINATION OF DICHLOROMETHANE IN A TUBULAR PHOTOREACTOR.

Sugawara,Suzuki,Ohashi

, p. 854 - 859 (1980)

The kinetics were studied with due consideration taken of the radial variation in light intensity across the reactor and with the proper selection of kinetic equations, including the recombination of dichloromethyl radicals as the dominant termination step. The dependence of the absorbed radiant energy on the chlorine concentration was well simulated by the use of the radial-light and line-source model. The predominance of the observed production rate of hydrogen chloride over that of chloroform was also reproduced well by the appropriately selected kinetic expressions, without any use of the long-chain approximation. This work is pertinent to photochemical reactor design.

Investigation of the behaviour of haloketones in water samples

Nikolaou, Anastasia D.,Lekkas, Themistokles D.,Kostopoulou, Maria N.,Golfinopoulos, Spyros K.

, p. 907 - 912 (2001)

The behaviour of the haloketones (HKs) 1,1-Dichloropropanone (1,1-DCP), 1,1,1-Trichloropropanone (1,1,1-TCP) and 1,3-Dichloropropanone (1,3-DCP) in ultrapure water solutions and in fortified drinking water samples was invest/gated. Their concentrations were determined at regular time intervals by the use of a gas chromatography-electron capture detector (GC-ECD) method. Two different temperatures were studied. The results have shown that HKs decompose both in ultrapure water solutions and in drinking water samples. The decomposition rates are higher in the drinking water samples, especially at higher temperature. 1,1,1-TCP is the compound which decomposes fastest followed by 1,3-DCP and 1,1-DCP. Chloroform was formed both in the ultrapure water solutions and in the drinking water samples, probably due to the decomposition of 1,1,1-TCP. In the drinking water samples, formation of chloral hydrate was also observed.

Patinkin,Lieber

, p. 2778 (1950)

The formation and control of disinfection by-products using chlorine dioxide

Chang, Chen-Yu,Hsieh, Yung-Hsu,Shih, I-Chen,Hsu, Shen-Sheng,Wang, Kuo-Hua

, p. 1181 - 1186 (2000)

In this study, chlorine dioxide (ClO2) was used as an alternative disinfectant with vanillic acid, p-hydroxybenzoic acid, and humic acid as the organic precursors in a natural aquatic environment. The primary disinfection by-products (DBPs) formed were trihalomethanes (THMs) and haloacetic acids (HAAs). Under neutral conditions (pH = 7) for vanillic acid, more total haloacetic acids (THAAs) than total trihalomethanes (TTHMs) were found, with a substantial increase during the later stages of the reaction. In the case of p-hydroxybenzoic acid, the amount of THAAs produced was minimal. Raising the concentration of ClO2 was not favorable for the control of THAAs in low concentrations of vanillic acid. ClO2 could reduce the total amount of TTHMs and THAAs for higher concentration of vanillic acid. It was found that the humic acid treatment dosage was not significant. Under alkaline conditions (pH = 9), the control of TTHMs and THAAs for the treatment of vanillic acid was better and more economical, however, an appreciable amount of inorganic by-products were observed. Under the same alkaline condition, the control of THAA for the treatment of p-hydroxybenzoic acid was not beneficial and for the treatment of humic acid was not significant. (C) 2000 Elsevier Science Ltd.

Mechanistic studies of the photocatalytic oxidation of trichloroethylene with visible-light-driven N-doped TiO2 photocatalysts

Joung, Soon-Kil,Amemiya, Takashi,Murabayashi, Masayuki,Itoh, Kiminori

, p. 5526 - 5534 (2006)

Visible-light-driven TiO2 photocatalysts doped with nitrogen have been prepared as powders and thin films in a cylindrical tubular furnace under a stream of ammonia gas. The photocatalysts thus obtained were found to have a band-gap energy of 2.95 eV. Electron spin resonance (ESR) under irradiation with visible light (λ ≥ 430 nm) afforded the increase in intensity in the visible-light region. The concentration of trapped holes was about fourfold higher than that of trapped electrons. Nitrogendoped TiO 2 has been used to investigate mechanistically the photocatalytic oxidation of trichloroethylene (TCE) under irradiation with visible light (λ ≥ 420 nm). Cl and O radicals, which contribute significantly to the generation of dichloroacetyl chloride (DCAC) in the photocatalytic oxidation of TCE under UV irradiation, were found to be deactivated under irradiation with visible light. As the main by-product. only phosgene was detected in the photocatalytic oxidation of TCE under irradiation with visible light. Thus, the reaction mechanism of TCE photooxidation under irradiation with visible light clearly differs markedly from that under UV irradiation. Based on the results of the present study, we propose a new reaction mechanism and adsorbed species for the photocatalytic oxidation of TCE under irradiation with visible light. The energy band for TiO2 by doping with nitrogen may involve an isolated band above the valence band.

Isoflurane enhances dechlorination of carbon tetrachloride in guinea-pig liver microsomes

Fujii, Kohyu,Rahman, Md. Mustafizur,Yuge, Osafumi

, p. 249 - 253 (1996)

Effect of isoflurane on the dechlorination of carbon tetrachloride to chloroform was investigated in the guinea-pip liver microsomes. Under anaerobic conditions, chloroform is produced from carbon tetrachloride through the microsomes in the presence of NADPH, and such production of chloroform was increased by the addition of isoflurane. The K(m) for the production of chloroform from carbon tetrachloride was decreased to 86% by isoflurane compared with the control; however the maximum velocity of chloroform production was also decreased to 50%. The formation of the 445 nm band in the mixture of reduced cytochrome P-450 and carbon tetrachloride, and cytochrome P-450 reduction by NADPH were both accelerated by isoflurane, without alteration of NADPH-cytochrome c reductase activity. These results indicate that trichloromethyl radical, an intermediate product of carbon tetrachloride, easily combines to the haeme part of cytochrome P-450, whereas the protein part combines to isoflurane after being reduced by NADPH, which results in acceleration of carbon tetrachloride dechlorination under a lower concentration of carbon tetrachloride. These results may have implications for other drugs that are administered during isoflurane anaesthesia.

Electrochemical investigation of the rate-limiting mechanisms for trichlomethylene and carbon tetrachloride reduction at iron surfaces

Li, Tie,Farrell, James

, p. 3560 - 3565 (2001)

The mechanisms involved in reductive dechlorination of carbon tetrachloride (CT) and trichloroethylene (TCE) at iron surfaces were studied to determine if their reaction rates were limited by rates of electron transfer. Chronoamperometry and chronopotentiometry analyses were used to determine the kinetics of CT and TCE reduction by a rotating disk electrode in solutions of constant halocarbon concentration. Rate constants for CT and TCE dechlorination were measured as a function of the electrode potential over a temperature range from 2 to 42 °C. Changes in dechlorination rate constants with electrode potential were used to determine the apparent electron-transfer coefficients at each temperature. The transfer coefficient for CT dechlorination was 0.22 ± 0.02 and was independent of temperature. The temperature independence of the CT transfer coefficient is consistent with a rate-limiting mechanism involving an outer-sphere electron-transfer step. Conversely, the transfer coefficient for TCE was temperature dependent and ranged from 0.06 ± 0.01 at 2 °C to 0.21 ± 0.02 at 42 °C. The temperature-dependent TCE transfer coefficient indicated that its reduction rate was limited by chemical dependent factors and not exclusively by the rate of electron transfer. In accord with a rate-limiting mechanism involving an electron-transfer step, the apparent activation energy (Ea) for CT reduction decreased with decreasing electrode potential and ranged from 33.0 ± 1.6 to 47.8 ± 2.0 kJ/mol. In contrast, the E, for TCE reduction did not decline with decreasing electrode potential and ranged from 29.4 ± 3.4 to 40.3 ± 3.9. The absence of a potential dependence for the TCE Ea supports the conclusion that its reaction rate was not limited by an electron-transfer step. The small potential dependence of TCE reaction rates can be explained by a reaction mechanism in which TCE reacts with atomic hydrogen produced from reduction of water.

Formation of chloroform by aqueous chlorination of organic compounds

Chaidou,Georgakilas,Stalikas,Saraci,Lahaniatis

, p. 587 - 594 (1999)

Thirty organic compounds were selected to investigate their chloroform formation characteristics during chlorination with sodium hypochlorite at pH-values 7.0 and 8.0. These experiments were conducted under conditions similar to those applied on the chlorination of raw water. The results indicated that the chloroform concentrations occurred by the all tested compounds was in the ppm range. The maximum levels of chloroform (11-13 mg/l) were determined during the reaction of resorcinol and phloroglucinol at pH-value 8.0.

Stimulatory effect of anesthetics on dechlorination of carbon tetrachloride in guinea-pig liver microsomes

Fujii, Kohyu

, p. 147 - 153 (1996)

Effects of the anesthetics isoflurane, enflurane, halothane and sevoflurane on the dechlorination of carbon tetrachloride to produce chloroform were investigated using guinea pig liver microsomes. Under anaerobic conditions, chloroform is produced from carbon tetrachloride by the microsomes in the presence of NADPH, and chloroform production from 86 μM carbon tetrachloride was enhanced to 146%, 133%, 123% and 115% by the addition of isoflurane, enflurane, halothane and sevoflurane, respectively. The half-life of oxidized cytochrome P450 which remained during the reduction by the addition of NADPH was shortened to 51%, 54%, 60% and 80% by isoflurane, enflurane, halothane and sevoflurane, respectively, without alteration of NADPH-cytochrome c reductase activity. These anesthetics hastened the onset of the 445 nm absorption band formation which was shown by microsomes with carbon tetrachloride in the presence of NADPH under anaerobic conditions. These results indicate that the anesthetics isoflurane, enflurane, sevoflurane and halothane stimulate the reduction of cytochrome P450 results in the acceleration of the carbon tetrachloride dechlorination. These results may have implications for other type II drugs that are administered during anesthesia.

Determination of the rate constant of the reaction of CCl2 with HCl

Gomez, Nicolas D.,D'Accurso, Violeta,Manzano, Francisco A.,Codnia, Jorge,Azcarate, M. Laura

, p. 382 - 388 (2014)

The rate constant of the reaction between CCl2 radicals and HCl was experimentally determined. The CCl2 radicals were obtained by infrared multiphoton dissociation of CDCl3. The time dependence of the CCl2 radic

Carbon tetrachloride transformation in a model iron-reducing culture: Relative kinetics of biotic and abiotic reactions

Adriaens,Bouwer,McCormick

, p. 403 - 410 (2002)

CCl4 (CT) is one of the most frequently encountered chlorinated solvent pollutants in groundwater. Contributions of biotic (cell-mediated) and abiotic (mineral-mediated) reactions CT transformation were investigated in a model iron-reducing system that utilized hydrous ferric oxide (HFO) as the electron acceptor, acetate as the substrate, and Geobacter metallireducens as a representative dissimilative iron-reducing bacteria. The mineral-mediated (abiotic) reaction was estimated to be 60-260-fold faster than the biotic reaction throughout the incubation period. A second member of the dissimilative iron-reducing bacteria, G. metallireducens, could biotically transform CT. However, in the presence of HFO, G. metallireducens drove CT transformation primarily through the formation of reactive mineral surfaces. This did not diminish the role that DIRB play even though it suggested that biologically mineral surfaces may be the principal agents of reductive transformation in iron-reducing environments. The results indicated that an alternative approach to stimulate reductive transformation of pollutants in iron-reducing environments might be to improve the formation of reactive biogenic minerals in situ. Other FeII species have been identified in iron-reducing environments that are also reactive with chlorinated solvents including the ferrous sulfides, green rusts, and sorbed FeII. It could also be possible to couple microbial iron reduction to reactive barrier design to exploit the ability of such bacteria to reactivate passivated metal surfaces.

Electrochemical reduction of tetrachloromethane. Electrolytic conversion to chloroform

Molina, Victor M.,Gonzalez-Arjona, Domingo,Roldan, Emilio,Dominguez, Manuel

, p. 279 - 292 (2002)

The feasibility of electrolytic removal of tetrachloromethane from industrial effluents has been investigated. A new method based on the electrochemical reductive dechlorination of CCl4 yielding chloroform is described. The main goal was not only to remove CCl4 but also to utilize the process for obtaining chloroform, which can be industrially reused. GC-MS analysis of the electrolysed samples showed that chloroform is the only product. Voltammetric experiments were made in order to select experimental conditions of the electrolysis. Using energetic and economic criteria, ethanol-water (1:4) and LiCl were found to be the optimum solvent and supporting electrolyte tested. No great differences were found while working at different pH values. Chronoamperometric and voltammetric experiments with convolution analysis showed low kf0 and α values for the reaction. A new differential pulse voltammetric peak deconvolution method was developed for an easier and faster analysis of the electrolysis products. Electrolysis experiments were carried out using both a bulk reactor and a through-flow cell. Thus, three different kinds of galvanostatic electrolyses were carried out. Under all conditions, CCl4 conversions ranging from 60 to 75% and good current efficiencies were obtained.

Micellar Effects on the Base-Catalyzed Oxidative Cleavage of a Carbon-Carbon Bond in 1,1-Bis(p-chlorophenyl)-2,2,2-trichloroethanol

Nome, Faruk,Schwingel, Erineu W.,Ionescu, Lavinel G.

, p. 705 - 710 (1980)

The base-catalyzed oxidative cleavage of 1,1-bis(p-chlorophenyl)-2,2,2-trichloroethanol (Dicofol) results in the formation of chloroform and 4,4'-dichlorobenzophenone.The reaction was studied in the presence of hexadecyltrimethylammonium bromide (CTAB) and hexadecyldimethyl(2-hydroxyethyl)ammonium bromide (CHEDAB), and catalytic factors of 200- and 345-fold, respectively, were obtained.The experimental results are rationalized in terms of an increase of the concentration of the reagents in the micellar phase.Sodium dodecyl sulfate (NaLS) inhibits the reaction, and dodecylcarnitine chloride (LCC) essentially does not alter the rate.The catalysis by cationic surfactants (CTAB, CHEDAB) is inhibited by added salts.The effectiveness of the salts in decreasing the rate constant is NaCl (excit.) = 27.7 kcal/mol, ΔG(excit.) = 19.8 kcal/mol, ΔS(excit.) = 25.9 eu) and for 1.0E-1 M CTAB (ΔH(excit.) = 26.7 kcal/mol, ΔG(excit.) = 20.8 kcal/mol, ΔS(excit.) = 19.6 eu) indicate that the rate decrease observed at high surfactant concentration is due to an entropic contribution to the free-energy term.

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Orndorff,Jessel

, p. 365 (1888)

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Formation of halocarbons in the methane-alkaline halide crystal system under UV radiation

Prilepsky,Povarov,Bredelev,Isidorov

, p. 1910 - 1913 (1998)

The possibility of formation of halomethanes upon the photostimulated reaction of halogen-containing minerals with methane was shown. The dynamics of accumulation of chloromethane, dichloromethane, and chloroform in model systems CH4-NaCl, CH4-sylvinite, and CH4-halite was studied experimentally. The kinetic parameters for the formation of methyl chloride were determined.

Reductive dechlorination of carbon tetrachloride in water catalyzed by mineral-supported biomimetic cobalt macrocycles

Ukrainczyk,Chibwe,Pinnavaia,Boyd

, p. 439 - 445 (1995)

Reductive dehalogenation, mediated by nonspecific biomimetic Co macrocycles, was studied in aqueous systems using carbon tetrachloride as a model compound. Two water-soluble macrocycles, cobalt tetrakis(N-methyl-4- pyridiniumyl)porphyrin (CoTMPyP) cation and cobalt tetrasulfophthalocyanine (CoPcTs) anion, were used as homogeneous and mineral-supported catalysts. The supported catalysts were prepared by exchanging CoTMPyP on the hectorite, fluorohectorite, and amorphous silica surface and by exchanging CoPcTs on the layered double hydroxide surface. Supported macrocycles were catalytically active in the dechlorination of CCl4 and the initial reaction rates followed Michaelis-Menten kinetics. The value of V(max) was correlated to the previously reported orientation of macrocycles in the interlayers and to the accessibility and electronic state of the metal center, following the order: CoTMPyP-silica > CoPcTs-layered double hydroxide > CoT-MPyP-fluorohectorite > CoTMPyP-hectorite. In both heterogeneous and homogeneous systems, volatile reaction products accounted for less than 30% of CCl4 degraded. In short- term experiments (2 h), homogeneous CoTMPyP was more active than heterogeneous catalysts, while homogeneous CoPcTs was deactivated due to aggregation, and degraded less CCl4 than supported CoPcTs. In long-term experiments (3 days), where large CCl4/macrocycle ratios were used, silica- supported CoTMPyP was more active than homogeneous CoTMPyP, suggesting that adsorption stabilized the catalyst.

Mechanisms and Products of Surface-Mediated Reductive Dehalogenation of Carbon Tetrachloride by Fe(II) on Goethite

Elsner, Martin,Haderlein, Stefan B.,Kellerhals, Thomas,Luzi, Samuel,Zwank, Luc,Angst, Werner,Schwarzenbach, Rene P.

, p. 2058 - 2066 (2004)

Aliphatic chlorinated hydrocarbons, including CCl4, are widespread groundwater contaminants. Mechanisms and product formation of CCl4 reduction by Fe(II) sorbed to goethite, which may lead to completely dehalogenated products or to form chloroform, a toxic product that is fairly persistent under anoxic conditions, were studied. A simultaneous transfer of two electrons and cleavage of two C-Cl bonds of CCl4 would completely circumvent chloroform production. Product formation pathways did not primarily depend on the competition between an initial one- and two-electron transfer, but on the presence of different radical scavengers and the properties of the mineral surface with respect to stabilization of reaction intermediates. Specific adsorption of major anions or pH effects could modify the capability of the goethite surface to stabilize short-lived radical intermediates.

Catalytic dechlorination of carbon tetrachloride in liquid phase with methanol as H-donor over AG/C catalyst

Lu, Mohong,Li, Xuebing,Chen, Bo,Li, Mingshi,Xin, Hongchuan,Song, Liang

, p. 7315 - 7318 (2014)

Catalytic hydrodechlorination of carbon tetrachloride (CCl4) is an effective measure to remove CCl4due to its pollutant character. The dechlorination of CCl4to dichloromethane (CH2Cl2) and chloroform (CHCl3) with a molar ratio of 3:2 was catalyzed by carbon-supported silver (Ag/C) catalyst in methanol solution. It was proposed from the catalytic results and characterization (X-ray diffraction, transmission electron microscopy and X-ray photoelectron spectroscopy) data that, the chloride ion is abstracted from adsorbed CCl4by Ag to form CCl3and CCl2radicals and silver chloride (AgCl), and meanwhile the dehydrogenation of methanol over Ag domains intrigues initial active Ag-H species and formaldehyde (HCHO): then the CCl3and CCl2radicals are combined with Ag-H to generate reaction products (CHCl3, and CH2Cl2) and Ag, and the dehydrogenated product HCHO facilitates the regeneration of formed AgCl to Ag with formation of carbon monoxide and hydrogen chloride. The catalyst can be recovered and recycled, and there was no significant decrease in catalytic activity and selectivity after 4threcycling. Copyright

Effects of polydiallyldimethyl ammonium chloride coagulant on formation of chlorinated by products in drinking water

Chang,Chiang,Chao,Liang

, p. 1333 - 1346 (1999)

The objectives of this research work was to evaluate the reduction of THM precursors by cationic p-DADMAC and determine the correlations between the chlorine demand and trihalomethane formation in the presence of electrolyte solutions and ambient light. The chlorine demand was found to be significantly reduced provided that the H2SO4 electrolyte was fed to the sample solutions. The amount of CHCl3 formation was also decreased when the Na2SO4 electrolyte was introduced in spite of the levels of light intensity. The p-DADMAC can not only effectively remove the turbidity but also reduce the formation of CHCl3. The optimum dosage of p-DADMAC for reducing the turbidity, TOC and CHCl3 in the humic acid and source water samples was determined and depended upon the nature of organics. The objectives of this research work was to evaluate the reduction of THM precursors by cationic p-DADMAC and determine the correlations between the chlorine demand and trihalomethane formation in the presence of electrolyte solutions and ambient light. The chlorine demand was found to be significantly reduced provided that the H2SO4 electrolyte was fed to the sample solutions. The amount of CHCl3 formation was also decreased when the Na2SO4 electrolyte was introduced in spite of the levels of light intensity. The p-DADMAC can not only effectively remove the turbidity but also reduce the formation of CHCl3. The optimum dosage of p-DADMAC for reducing the turbidity, TOC and CHCl3 in the humic acid and source water samples was determined and depended upon the nature of organics.

Acetone-photosensitized reduction of carbon tetrachloride by 2-propanol in aqueous solution

Betterton,Hollan,Arnold,Gogosha,McKim,Liu

, p. 1229 - 1233 (2000)

The kinetics and mechanism of the reductive dehalogenation of CCl4 to chloroform were studied in the presence of aqueous acetone and 2-propanol, which was added as a hydrogen donor. The rate of reduction was very fast, stoichiometrically converted 3 mM CCl4 to chloroform in ~ 2 min. The zero-order reaction occurred at 2.7 x 10 -6 M/sec rate under typical conditions (0.69 M acetone, 5.7 M 2-propanol, 3 mM CCl4) using a 75 W Xe lamp. The mechanism was first order in CCl4 near the end of the reaction. The zero-order reaction rate increased with acetone, 2-propanol, and with absorbed light intensity. Other combinations of carbonyls, alcohols, and halogenated organics such as methyl ethyl ketone, methanol, ethanol, 1-propanol, and 1-butanol are also effective in dehalogenation via this process. Relative rates of dehydrogenation for a series of chlorinated methanes and ethanes such as trichloroethylene and perchloroethylene are presented.

PROTON-TRANSFER MECHANISM IN THE DECARBOXYLATION OF AMMONIUM TRICHLOROACETATE IN ACETONITRILE

Pawlak, Zenon,Fox, Malcolm F.,Tusk, Maria,Kuna, Stevan

, p. 1987 - 1994 (1983)

The rate constants, k, for the decomposition of ammonium trichloroacetate in acetonitrile were determined at 298 K where B is an N-base.The first-order decarboxylation of trichloroacetic acid in the presence of N-bases is strongly deopendent upon proton transfer in complexes.Discussion of the rate constants, k, obtained shows 3 types of complexes in the proton-transfer mechanism, i.e. a symmetrically positioned proton, and without proton transfer for 2 cases: .The sigmoidal curve of rate constants, -log k, plotted against (pKa)AN describes the location of the proton in the hydrogen bridge.The behaviour of (CCl3COOHR)(1-) complexes has many similarities to the molecular complexes, CCl3COOHB, discussed above.Implications of these results for carboxylate additives in overbased lubricating oils are discussed.

Sasson,Rempel

, p. 3221 (1974)

The role of hydrogen atoms in CIDNP effects in the reaction of diisobutylaluminum hydride with CCl4

Sadykov,Teregulov

, p. 2040 - 2042 (1998)

Integral polarization of chloroform, methylene dichloride, and pentachloroethane was observed in the 1H NMR spectra during the exothermal reaction of a 1 M solution of Bui2AlH in 1,4-dioxane with CCl4. CIDNP was shown to appear in the diffusion radical pair of the hydrogen atom and trichloromethyl radical.

Enhanced dechlorination of carbon tetrachloride and chloroform in the presence of elemental iron and Methanosarcina barkeri, Methanosarcina thermophila, or Methanosaeta concillii

Novak,Daniels,Parkin

, p. 1438 - 1443 (1998)

Previous experiments in our laboratory have demonstrated that the rate and extent of carbon tetrachloride (CT) and chloroform (CF) dechlorination were enhanced when a methanogenic enrichment culture and iron (Fe0) were incubated together. Batch experiments with three pure cultures of methanogens, Methanosarcina barkeri, Methanosarcina thermophila, and Methanosaeta concillii were performed to determine how this enhanced transformation occurred. When hydrogen (H2) was added as an electron donor, degradation of CT for all organisms and CF for M. thermophila was more rapid. H2 was produced from the oxidation of iron, which therefore served as an H2 source for the organisms, enhancing the transformation of CT and CF. Experiments with M. thermophila and M. concillii, which could not grow on H2-CO2 under the conditions tested, showed that H2 could serve as an electron donor for dechlorination of CT and CF with these organisms as well. Experiments with supernatants from M. thermophila grown with and without iron indicated the presence of an excreted biomolecule active in the enhanced transformation of CT and CF. Previous experiments in our laboratory have demonstrated that the rate and extent of carbon tetrachloride (CT) and chloroform (CF) dechlorination were enhanced when a methanogenic enrichment culture and iron (Fe0) were incubated together. Batch experiments with three pure cultures of methanogens, Methanosarcina barkeri, Methanosarcina thermophila, and Methanosaeta concillii were performed to determine how this enhanced transformation occurred. When hydrogen (H2) was added as an electron donor, degradation of CT for all organisms and CF for M. thermophila was more rapid. H2 was produced from the oxidation of iron, which therefore served as an H2 source for the organisms, enhancing the transformation of CT and CF. Experiments with M. thermophila and M. concillii, which could not grow on H2-CO2 under the conditions tested, showed that H2 could serve as an electron donor for dechlorination of CT and CF with these organisms as well. Experiments with supernatants from M. thermophila grown with and without iron indicated the presence of an excreted biomolecule active in the enhanced transformation of CT and CF.

Fachinetti, G.,Floriani, G.

, (1972)

Tedder,Watson

, p. 1215 (1966)

A study of the Atherton-Todd reaction mechanism

Troev,Kirilov,Roundhill

, p. 1284 - 1285 (1990)

-

Dechlorination of carbon tetrachloride by Fe(II) associated with goethite

Gorby,Amonette,Workman,Kennedy,Fruchter

, p. 4606 - 4613 (2000)

Carbon tetrachloride (CT) was dechlorinated to chloroform (CF) under anoxic conditions by Fe(II) which was sorbed to the surface of goethite (α-FeOOH). There was no reaction when goethite was absent and Fe(II) was present. Experiments were carried out with goethite at 30°C in which the total amount of Fe(II) in the system, the amount of sorbed Fe(II), the pH, and the density of sorbed Fe(II) were varied. Regeneration of sorbed Fe(II) occurred when dissolved Fe2+ was available and maintained pseudo-first-order conditions with respect to CT. Analysis of the CT loss rates for experiments with sorbed-Fe(II) regeneration revealed the rate-determining step to be first order with respect to CT, second order with respect to the volumetric concentration of sorbed Fe(II), and zero order with respect to H+ for pH 4.2-7.3. Normalization of the observed rate constants to account for various goethite concentrations gave reaction orders of zero and one, respectively for H+ and CT, and a second-order reaction with respect the density of sorbed Fe(II). The rate-determining step was a termolecular two-electron-transfer reaction involving two Fe2+ ions sorbed to adjacent sites on the goethite surface and CCl4 molecule approaching the surface. The primary role of the goethite surface was to catalyze the reaction by fixing the position of the two charged reactants in a geometry suitable for reaction with CT. In separate studies, biogenic Fe(II) formed by the enzymatic reduction of goethite by the Fe(III)-reducing bacterium Shewanella alga, strain BrY, dechlorinated CT. Dechlorination reactions in Fe(III)-reducing environments might indirectly result from the chemical or enzymatic reduction of Fe(III)-bearing minerals, e.g., goethite.

Chlorination of phenols: Kinetics and formation of chloroform

Gallard, Herve,von Gunten, Urs

, p. 884 - 890 (2002)

The kinetics of chlorination of several phenolic compounds and the corresponding formation of chloroform were investigated at room temperature. For the chlorination of phenolic compounds, second-order in the phenolic compound. The rate constants of the reactions of HOCl with phenol and phenolate anion and the rate constant of the acid-catalyzed reaction were determined in the pH range 1-11. The second-order rate constants for the reaction HOCl + phenol varied between 0.02 and 0.52 M-1 s-1, for the reaction HOCl and phenolate between 8.46 × 101 and 2.71 × 104 M-1 s-1. The rate constant for the acid-catalyzed reaction varied between 0.37 M-2 s-1 to 6.4 × 103 M-2 s-1. Hammett-type correlations were obtained for the reaction for the reaction of HOCl with phenolate (log(k) = 4.15-3.00 × ∑σ). The formation of chloroform could be interpreted with a second-order model, first-order in chlorine, and first-order in chloroform precursors. The corresponding rate constants varied between k > 100 M-1 s-1 for resorcinol to 0.026 M-1 s-1 to p-nitrophenol at pH 8.0. It was found that the rate-limiting step of chloroform formation is the chlorination of the chlorinated ketones. Yields of chloroform formation depend on the type and position of the substituents and varied between 2 and 95% based on the concentration of the phenol.

Chemistry of reduced monomeric and dimeric cobalt complexes supported by a PNP pincer ligand

Rozenel, Sergio S.,Padilla, Rosa,Arnold, John

, p. 11544 - 11550 (2013)

The reduction chemistry of cobalt complexes with HPNP (HPNP = HN(CH 2CH2PiPr2)2) as a supporting ligand is described. Reaction of [(HPNP)CoCl2] (1) with n-BuLi generated both the deprotonated Co(II) species [(PNP)CoCl] (2) along with the Co(I) complex [(HPNP)CoCl] (3). Products resulting from reduction of 2 with KC8 vary depending upon the atmosphere under which the reduction is performed. Monomeric square planar [(PNP)CoN2] (4) is obtained under dinitrogen, whereas dimeric [(PNP)Co]2 (5) is formed under argon. Over time, 5 activates a C-H bond in the PNP ligand to form the species [Co(H)(μ-PNP)(μ-iPr2PCH2CH 2NCHCH2PiPr2)Co] (6). We also observed the oxidative addition of H-Si bond to complex 3 to form [(HPNP)CoCl(H)SiH2Ph] (7). 1H NMR studies showed that species 7 is in equilibrium with 3 and silane in solution. Complex 3 can be oxidized with AgBPh4 to generate {(HPNP)CoCl}BPh4 (8), a square planar species with a formal electron count of 15 electrons.

Anschuetz

, p. 3512 (1892)

Catalytic carbon-halogen bond cleavage chemistry by redox-active polyoxometalates

Sattari, Daryush,Hill, Craig L.

, p. 4649 - 4657 (1993)

The use of redox-active polyoxotungstate complexes to effect the cleavage of carbon-halogen bonds (C-X, X = Cl or Br) by three distinct modes is demonstrated for the first time. The first mode involves direct thermal reaction of halocarbon substrates with H2W10O324- or α-HPW12O403-. The rate law for CCl4 dehalogenation is V = k(H2W10O324-)(CCl4) and k(H2W10O324-)/k(α-HPW 12O403-) = 2.8. Several lines of evidence collectively establish that carbon-halogen bond cleavage likely involves dissociation electron transfer for the mode 1 reactions, although halogen atom abstraction (atom transfer) cannot be ruled out. The evidence includes comparisons of kinetic profiles for dehalogenation rate versus halocarbon substrate structure, relative reactivities of substrates (polyhalogenated more reactive (>) than monohalogenated compounds; tertiary > secondary > primary halides; bromides > chlorides), and other product distribution data including one "radical clock" reaction, in addition to the rate law. Interestingly one carbocation derived product, N-tert-butylacetamide, is generated in the debromination of tert-butyl bromide in acetonitrile. The second and third modes of dehalogenation involve extensions of previously reported polyoxometalate photoredox processes, and both modes are catalytic extensions of existing effective stoichiometric dehalogenation processes. The second mode proceeds by a complex rate law and involves photocatalytic transformation of organic halide (halocarbons) into inorganic halide (HX) coupled with the oxidation of sacrificial organic reductants (secondary alcohols or tertiary amides). The second mode essentially defines a method to catalytically generate reducing radicals under mild conditions; the radicals are the principal dehalogenating species. The third mode of dehalogenation is similar to the second mode but run in the presence of O2. Here the reduced polyoxotungstates reduce O2 to superoxide which then dehalogenates substrate. The third mode effects catalytic dehalogenation of a wide range of halocarbons.

Chang et al.

, p. 2070 (1971)

Photoeffects on the reduction of carbon tetrachloride by zero-valent iron

Balko, Barbara A.,Tratnyek, Paul G.

, p. 1459 - 1465 (1998)

While reduction of chlorinated hydrocarbons by zero-valent iron in water is strongly influenced by the oxide layer at the metal-water interface, the role of the oxide in the dechlorination mechanism has not been fully characterized. In this paper, we investigate the semiconducting properties of the oxide layer on granular iron and show how the electronic properties of the oxide affect electron transfer to aqueous CCl4. Specifically, we determine whether conduction-band electrons contribute to the reduction of CCl4 by using light to increase the number of conduction-band electrons at the oxide surface and measuring how this treatment affects the rate and products of CCl4 degradation. We find that photogenerated conduction-band electrons do degrade CCl4 and, more importantly, shift the product distribution to more completely dechlorinated products that are indicative of two-electron transfer with a dichlorocarbene intermediate. Since the photogenerated electrons give different reduction products than the dark reducers, we conclude that the latter must not be conduction-band electrons. Further investigation of the reduction with photogenerated electrons is carried out by adding hole scavengers to the system. Isopropyl alcohol reacts with photogenerated holes to yield the ?±-hydroxyalkyl radical, which is known to reduce CCl4. With isopropyl alcohol present, we observe faster degradation of CCl4 with higher light intensity. Since no such increase is seen without isopropyl alcohol, the rate of CCl4 degradation by conduction-band electrons in water must not be limited by the number of photogenerated electron-hole pairs but rather by electron transfer from the oxide conduction band to CCl4.

Reductive dehalogenation of chlorinated methanes by iron metal

Matheson,Tratnyek

, p. 2045 - 2053 (1994)

Reduction of chlorinated solvents by fine-grained iron metal was studied in well-mixed anaerobic batch systems in order to help assess the utility of this reaction in remediation of contaminated groundwater. Iron sequentially dehalogenates carbon tetrachloride via chloroform to methylene chloride. The initial rate of each reaction step was pseudo-first-order in substrate and became substantially slower with each dehalogenation step. Thus, carbon tetrachloride degradation typically occurred in several hours, but no significant reduction of methylene chloride was observed over 1 month. Trichloroethene (TCE) was also dechlorinated by iron, although more slowly than carbon tetrachloride. Increasing the clean surface area of iron greatly increased the rate of carbon tetrachloride dehalogenation, whereas increasing pH decreased the reduction rate slightly. The reduction of chlorinated methanes in batch model systems appears to be coupled with oxidative dissolution (corrosion) of the iron through a largely diffusion-limited surface reaction.

Kinetics of carbon tetrachloride reduction at an oxide-free iron electrode

Scherer, Michelle M.,Westall, John C.,Ziomek-Moroz, Margaret,Tratnyek, Paul G.

, p. 2385 - 2391 (1997)

To address some of the fundamental questions regarding the kinetics of reduction of contaminants by zero-valent iron (Fe0), we have taken advantage of the mass transport control afforded by a polished Fe0 rotating disk electrode (RDE) in an electrochemical cell. The kinetics of carbon tetrachloride (CCl4) dechlorination at an Fe0 RDE were studied in pH 8.4 borate buffer at a potential at which an oxide film would not form. In this system, the cathodic current was essentially independent of electrode rotation rate, and the measured first-order heterogeneous rate constant for the chemical reaction (k(ct) = 2.3 x 10-5 cm s-1) was less than the estimated rate constant for mass transfer to the surface. Thus, for the conditions of this study, the rate of reduction of CCl4 by oxide-free Fe0 appears to be dominated by reaction at the metal-water interface rather than by transport to the metal surface. Activation energies for reduction of CCl4 and hexachloroethane by oxide-covered granular Fe0 (measured in batch systems) also indicate that overall rates are limited by reaction kinetics. Since mass transport rates vary little among the chlorinated solvents, it is likely that variation in k(ct) is primarily responsible for the wide range of dechlorination rates that have been reported for batch and column conditions. To address some of the fundamental questions regarding the kinetics of reduction of contaminants by zero-valent iron (Fe0), we have taken advantage of the mass transport control afforded by a polished Fe0 rotating disk electrode (RDE) in an electrochemical cell. The kinetics of carbon tetrachloride (CCl4) dechlorination at an Fe0 RDE were studied in pH 8.4 borate buffer at a potential at which an oxide film would not form. In this system, the cathodic current was essentially independent of electrode rotation rate, and the measured first-order heterogeneous rate constant for the chemical reaction (kct = 2.3×10-5 cm s-1) was less than the estimated rate constant for mass transfer to the surface. Thus, for the conditions of this study, the rate of reduction of CCl4 by oxide-free Fe0 appears to be dominated by reaction at the metal - water interface rather than by transport to the metal surface. Activation energies for reduction of CCl4 and hexachloroethane by oxide-covered granular Fe0 (measured in batch systems) also indicate that overall rates are limited by reaction kinetics. Since mass transport rates vary little among the chlorinated solvents, it is likely that variation in kct is primarily responsible for the wide range of dechlorination rates that have been reported for batch and column conditions.

Kinetics of Radiation-Induced Hydrogen Abstraction by CCl3 Radicals in the Liquid Phase. Secondary Alcohols

Feilman, Liviu,Alfassi, Zeev B.

, p. 3060 - 3063 (1981)

The dependence of the yield of products in the γ-radiation-induced free-radical reactions in carbon tetrachloride solutions of secondary alcohols on the alcohol concentration and the temperature was studied in the range of 0.05-0.6 M and 30-150 deg C.The rate constant for the reaction CCl3 + R1R2COH -> CHCl3 + R1R2COH (k1) was found as logk1 (M-1 s-1) = 8.63-9.1, where Τ = 2.303RT kcal mol-1.The activation energy is 1.8 +/- 0.3 kcal mol-1 lower than for secondary hydrogens in alkanes and about the same as for the tertiary hydrogens in 2,3-dimethylbutane.

Reductive dechlorination of carbon tetrachloride by cobalamin(II) in the presence of dithiothreitol: mechanistic study, effect of redox potential and pH

Assaf-Anid,Hayes,Vogel

, p. 246 - 252 (1994)

A mechanistic study of the reductive dechlorination of carbon tetrachloride by vitamin B12 (cyanocobalamin) in the presence of dithiothreitol was conducted as a function of redox potential and pH. The solution redox potential decreased both with an increase in the total concentration of dithiothreitol present and with an increase in pH. The pseudo-first-order rate constant of carbon tetrachloride disappearance increased with decreasing redox potential. The predominant cobalt species present under the reaction conditions was cobalamin(II) (vitamin B12r), as confirmed by spectrophotometric analysis, suggesting a one-electron reduction of vitamin B12 and the involvement of two vitamin B12 molecules per reacting carbon tetrachloride molecule. -from Authors

Synthesis of Decorated Carbon Structures with Encapsulated Components by Low-Voltage Electric Discharge Treatment

Bodrikov, I. V.,Pryakhina, V. I.,Titov, D. Yu.,Titov, E. Yu.,Vorotyntsev, A. V.

, p. 60 - 69 (2022/03/17)

Abstract: Polycondensation of complexes of chloromethanes with triphenylphosphine by the action of low-voltage electric discharges in the liquid phase gives nanosized solid products. The elemental composition involving the generation of element distribution maps (scanning electron microscopy–energy dispersive X?ray spectroscopy mapping) and the component composition (by direct evolved gas analysis–mass spectrometry) of the solid products have been studied. The elemental and component compositions of the result-ing structures vary widely depending on the chlorine content in the substrate and on the amount of triphenylphosphine taken. Thermal desorption analysis revealed abnormal behavior of HCl and benzene present in the solid products. In thermal desorption spectra, these components appear at an uncharacteristically high temperature. The observed anomaly in the behavior of HCl is due to HCl binding into a complex of the solid anion HCI-2 with triphenyl(chloromethyl)phosphonium chloride, which requires a relatively high temperature (up to 800 K) to decompose. The abnormal behavior of benzene is associated with its encapsulated state in nanostructures. The appearance of benzene begins at 650 K and continues up to temperatures above 1300?K.

Revisiting Alkane Hydroxylation with m-CPBA (m-Chloroperbenzoic Acid) Catalyzed by Nickel(II) Complexes

Itoh, Mayu,Itoh, Shinobu,Kubo, Minoru,Morimoto, Yuma,Shinke, Tomoya,Sugimoto, Hideki,Wada, Takuma,Yanagisawa, Sachiko

, p. 14730 - 14737 (2021/09/29)

Mechanistic studies are performed on the alkane hydroxylation with m-CPBA (m-chloroperbenzoic acid) catalyzed by nickel(II) complexes, NiII(L). In the oxidation of cycloalkanes, NiII(TPA) acts as an efficient catalyst with a high yield and a high alcohol selectivity. In the oxidation of adamantane, the tertiary carbon is predominantly oxidized. The reaction rate shows first-order dependence on [substrate] and [NiII(L)] but is independent on [m-CPBA]; vobs=k2[substrate][NiII(L)]. The reaction exhibited a relatively large kinetic deuterium isotope effect (KIE) of 6.7, demonstrating that the hydrogen atom abstraction is involved in the rate-limiting step of the catalytic cycle. Furthermore, NiII(L) supported by related tetradentate ligands exhibit apparently different catalytic activity, suggesting contribution of the NiII(L) in the catalytic cycle. Based on the kinetic analysis and the significant effects of O2 and CCl4 on the product distribution pattern, possible contributions of (L)NiII?O. and the aroyloxyl radical as the reactive oxidants are discussed.

PRODUCTION OF CARBON TETRACHLORIDE FROM NATURAL GAS

-

Paragraph 0058, (2020/07/07)

The present invention provides processes to prepare carbon tetrachloride by the chlorination of natural gas in the presence of a diluent.

A process of preparing methyl chloride using multistage reaction

-

Paragraph 0092-0100; 0112; 0120, (2020/06/10)

The present invention relates to a method of producing methyl chloride by multistage reactions. The method of the present invention comprises: a) a chlorination step for sufficiently increasing the conversion rate of methane, which is an initial reactant; and b) a subsequent reaction step for actively utilizing hydrogen chloride (HCl), which is a hazardous byproduct of chlorination, efficiently treating harmful hydrogen chloride, and at the same time, improving the overall production of methyl chloride.COPYRIGHT KIPO 2020

Control of methane chlorination with molecular chlorine gas using zeolite catalysts: Effects of Si/Al ratio and framework type

Kwon, Seungdon,Chae, Ho-Jeong,Na, Kyungsu

, p. 111 - 117 (2020/01/31)

CH4 chlorination with Cl2 gas is used for the production of chlorinated products via C–H bond activation in CH4. Due to the high reactivity of Cl2, this reaction can occur spontaneously under UV irradiation or with mild thermal energy even in the absence of a catalyst via a free radical-mediated chain reaction mechanism that undesirably causes excessive chlorination of the CH4 and is thus non-selective. In this work, CH4 chlorination is investigated using HY and MFI zeolites with various Si/Al ratios, by which the reaction is catalytically controlled for selective production of the mono-chlorinated product (CH3Cl). Depending on the framework type, Si/Al ratio of the zeolites, and reaction conditions, different degrees of CH4 conversion, CH3Cl selectivity, and hence CH3Cl yield were achieved, by which systematic relationships between the catalyst properties and performance were discovered. A high aluminum content facilitated the production of CH3Cl with up to ~20 % yield at a high gas hourly space velocity of 2400 cm3gcat?1 h?1 with a CH4/Cl2 ratio of 1 at 350 °C. HY zeolites generally furnished a slightly higher CH3Cl yield than MFI zeolites, which can be attributed to the larger micropores of the HY zeolites that support facile molecular diffusion. With various flow rates and ratios of CH4 and Cl2, the CH4 conversion and CH3Cl selectivity changed simultaneously, with a trade-off relationship. Unfortunately, all zeolite catalysts suffered from framework dealumination due to the HCl produced during the reaction, but it was less pronounced for the zeolites having a low aluminum content. The results shed light on the detailed roles of zeolites as solid-acid catalysts in enhancing CH3Cl production during electrophilic CH4 chlorination.

Process route upstream and downstream products

Process route

tetrachloromethane
56-23-5

tetrachloromethane

1,1,1,5-tetrachloro-3-methylhexane
13275-22-4

1,1,1,5-tetrachloro-3-methylhexane

isopropyl chloride
75-29-6

isopropyl chloride

chloroform
67-66-3,8013-54-5

chloroform

1,1,1-trichloro-butane
13279-85-1

1,1,1-trichloro-butane

1,1,1,3-tetrachlorobutane
13275-19-9

1,1,1,3-tetrachlorobutane

1,1,1-trichloro-3-methyl-hexane
13275-20-2

1,1,1-trichloro-3-methyl-hexane

Conditions
Conditions Yield
With di-tert-butyl peroxide; triphenylphosphine; at 140 ℃; for 1h; Product distribution; Mechanism; chain termination in the telomerization of title compound;
4.0 % Chromat.
7.9 % Chromat.
With tungsten hexacarbonyl; triphenylphosphine; at 140 ℃; for 1h; Product distribution; Mechanism; chain termination in the telomerization of title compound;
3.6 % Chromat.
9.2 % Chromat.
ethanol
64-17-5

ethanol

pentachloro-2-(trimethylsiloxy)propene
87651-34-1

pentachloro-2-(trimethylsiloxy)propene

chloroform
67-66-3,8013-54-5

chloroform

ethyl trimethylsilyl ether
1825-62-3

ethyl trimethylsilyl ether

ethyl 1,1-dichloroacetate
535-15-9

ethyl 1,1-dichloroacetate

Conditions
Conditions Yield
With triethylamine; for 8h; Yields of byproduct given; Heating;
71%
With triethylamine; for 8h; Yield given; Heating;
71%
2,2,2-trichloro-1-[4-(dimethylamino)phenyl]ethan-1-ol
66379-84-8

2,2,2-trichloro-1-[4-(dimethylamino)phenyl]ethan-1-ol

chloroform
67-66-3,8013-54-5

chloroform

4-dimethylamino-benzaldehyde
100-10-7

4-dimethylamino-benzaldehyde

Conditions
Conditions Yield
With sodium hydroxide; In water; at 25 ℃; Kinetics; Mechanism; ΔH(excit.), ΔS(excit.), ΔG(excit.), variation of hydroxide concentration;
4-Nitrophenyl phenyl(trichloromethyl)phosphinate
81344-26-5

4-Nitrophenyl phenyl(trichloromethyl)phosphinate

chloroform
67-66-3,8013-54-5

chloroform

(4-Nitrophenyl)phenylphosphonic acid
40103-72-8

(4-Nitrophenyl)phenylphosphonic acid

p-nitrophenyl phenyl phosphonate
57072-35-2

p-nitrophenyl phenyl phosphonate

Conditions
Conditions Yield
Rate constant; Product distribution; hydrolysis; various pH conditions;
chloroform
67-66-3,8013-54-5

chloroform

hexachloroethane
67-72-1

hexachloroethane

benzyl bromide
100-39-0

benzyl bromide

Conditions
Conditions Yield
With 2,2'-azobis(isobutyronitrile); Bromotrichloromethane; at 80 ℃; for 8h; Product distribution; Mechanism; reaction in the presence of ethylene oxide;
trichloromethylphosphonous dichloride
3582-11-4

trichloromethylphosphonous dichloride

butan-1-ol
71-36-3

butan-1-ol

dibutyl hydrogen phosphite
1809-19-4

dibutyl hydrogen phosphite

n-Butyl chloride
109-69-3

n-Butyl chloride

chloroform
67-66-3,8013-54-5

chloroform

Conditions
Conditions Yield
75.4%
tetrachloromethane
56-23-5

tetrachloromethane

decane
124-18-5

decane

dichloromethane
75-09-2

dichloromethane

chloroform
67-66-3,8013-54-5

chloroform

decyl chloride
1002-69-3

decyl chloride

hexachloroethane
67-72-1

hexachloroethane

Conditions
Conditions Yield
With di-μ-chlorobis[bis(dimethylformamide)chlorocopper(II)]; at 159.9 ℃; Product distribution; effect of additives (ionol, O2), other catalysts; kinetic curves;
4'-methylisobutyrophenone
50390-51-7

4'-methylisobutyrophenone

chloroform
67-66-3,8013-54-5

chloroform

terephthalic acid
100-21-0

terephthalic acid

acetic acid
64-19-7,77671-22-8

acetic acid

Conditions
Conditions Yield
2,2,2-trichloro-1-(4-methoxyphenyl)ethan-1-ol
14337-31-6

2,2,2-trichloro-1-(4-methoxyphenyl)ethan-1-ol

chloroform
67-66-3,8013-54-5

chloroform

4-methoxybenzoic acid
100-09-4

4-methoxybenzoic acid

Conditions
Conditions Yield
Behandeln des Produkts mit KOH;
2,2,2-trichloro-1-[4-(dimethylamino)phenyl]ethan-1-ol
66379-84-8

2,2,2-trichloro-1-[4-(dimethylamino)phenyl]ethan-1-ol

chloroform
67-66-3,8013-54-5

chloroform

4-dimethylamino-benzaldehyde
100-10-7

4-dimethylamino-benzaldehyde

Conditions
Conditions Yield

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