67471-27-6Relevant academic research and scientific papers
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.
Isomerization of perchlorohexatriene in three consecutive rearrangements to perchloro-2-vinylbutadiene
Schollmeyer, Dieter,Detert, Heiner
supporting information, p. 843 - 846 (2017/02/18)
Perchlorohexatriene isomerizes in three subsequent rearrangements to perchloro-2-vinylbutadiene. A radical-induced Z-E-equilibration of linear perchlorohexatrienes is followed by cyclization to a methylenecyclopentene. Under flash-vacuum pyrolysis conditions, a ring contraction to 1,2-dimethylenecyclobutane occurs. In the condensed phase, a radical-induced ring opening generates the branched perchloro-vinylbutadiene. All compounds are converted to hexachlorobenzene, but only at very high temperatures.
Thermal rearrangements of perchlorohexatrienes-structures and experimental and theoretical evaluation of pathways to isomerization and cyclization
Detert, Heiner,Lenoir, Dieter,Zipse, Hendrik
experimental part, p. 1181 - 1190 (2009/07/11)
We have prepared trans- (1) and cis-octachloro-1,3,5-hexatriene (2) by known routes and studied their thermal behavior experimentally and theoretically by ab initio calculations. The three double bonds in 1 and 2 are completely decoupled due to steric hindrance by the eight Cls, as indicated by calculations as well as the single-crystal X-ray structure of 1. The cis isomer 2 can be isomerized to the trans isomer 1 by heating it to 220-250 °C either neat or dissolved in highboiling solvents, leading to a roughly 2:1 mixture of trans and cis isomers. Calculations at several different levels of theory predict 1 and 2 to be isoenergetic within 2 kJmol-1. Unimolecular cis/trans isomerization is predicted to occur through an unusual vinylcyclobutene intermediate 7, whose formation faces a barrier of more than 150 kJmol -1, but whose stability is comparable to that of 1 and 2. The isomerization rate is strongly enhanced by the addition of small amounts of Br2 or Cl2 or by 3 and can be explained by a radical-induced isomerization mechanism. The heating of trienes 1 and 2 to 250 °C leads to cyclization, yielding 71% of the cyclopentene isomer 3. Compound 3 can be dechlorinated by treatment with copper powder to give fulvene derivative 4. Using flash vacuum pyrolysis, the thermal conversion of trienes 1 and 2 to hexachlorobenzene (5) occurs at higher temperatures between 600-1000 °C, likely via perchlorinated 1,3-cyclohexadiene (6) as an intermediate. The elimination of molecular Cl2 from 3 and 6 requires very high activitation energies in agreement with calculations. Wiley-VCH Verlag GmbH & Co. KGaA, 2009.
METHOD FOR THE PRODUCTION OF 1,3,5-TRIFLUORO-2,4,6-TRICHLOROBENZENE FROM FLUOROBENZENE DERIVATIVES
-
Page/Page column 9, (2008/06/13)
Method for the production of 1,3,5-trifluoro-2,4,6-trichlorobenzene from fluorobenzene, comprising steps A) and B): A) chlorination of fluorobenzene derivatives of formula (II), in which X = fluorine or H, Z = nitro, bromo or chloro and n = 0 or 1-4 and B) fluorination of the distillation residue and separation by distillation of the 1,3,5-trifluoro-2,4,6-trichlorobenzene thus produced.
On assembling polychlorinated aromatic hydrocarbons from carbon tetrachloride via dichlorocarbene intermediary by a solvothermal reaction: A reaction pattern from carbene-ylide interconversion
Xie, Su-Yuan,Peng, Yin,Chen, Meng,Huang, Rong-Bin,Chow, Yuan L.,Zheng, Lan-Sun
, p. 1400 - 1407 (2007/10/03)
(Chemical Equation Presented) The forced one-electron reduction of carbon tetrachloride with sodium in a sealed steel vessel is shown to have a narrow window of conditions to arrest the reaction at the polychlorinated aromatic hydrocarbons (PCAHs), as well as to prevent the reaction from proceeding all the way to the final stage of graphite and other carbon solids. The intermediates are quenched with toluene or benzene to give electrophilic substitution products and with water to give a quinomethine as the major product. The product pattern leads us to propose the carbene, perchlorobenzo[c,d]pyren-6-ylidene, or its reversible dimer as the major intermediate among others, that survives the severe conditions until coming into contact with these nucleophiles. Mainly from aromatic resonance stabilization, the carbene is proposed to have a delocalized singlet state analogous to a ylide electronic structure and, thus, undergoes observed ionic reactions instead of typical carbene reactions. This work serves as a mechanistic link on the structural evolution of carbon networks between molecular chemistry and nanomaterial chemistry.
Formation of PCDDs and PCDFs during the combustion of polyvinylidene chloride and other polymers in the presence of HCl
Ohta, Minoru,Oshima, Shozo,Osawa, Naoki,Iwasa, Toshio,Nakamura, Tadashi
, p. 1521 - 1531 (2007/10/03)
PVDC and three non-chlorinated polymers (PP, PET, and PA) were incinerated at 700-850°C in a laboratory-scale quartz tubular furnace in the presence of HCl (ca. 500 ppm?0.8 mg/l), and the gas-phase formation of PCDD/Fs, their putative precursors and their homologue profiles were investigated. The addition of HCl had little or no apparent effect on the level of PCDD/Fs formation during PVDC combustion, and their homologue profiles were quite different from those of the three non-chlorinated polymers. With PVDC, O 8CDD and particularly O8CDF were by far most prevalent, apparently as a result of the selective formation of the precursors. With each of the three non-chlorinated polymers, combustion at 800°C or higher in the presence of HCl resulted in PCDD/Fs formation at levels equaling or exceeding those observed with PVDC. In trials made with one of them (PP) under the same conditions but using a large polymer sample (100 mg vs 20 mg in all other trials), the level of PCDD/Fs formation was far higher than with the smaller polymer samples, and thus demonstrated the importance of appropriate combustion conditions for polymer incineration.
Formation and destruction of chlorinated pollutants during sewage sludge incineration
Fullana, Andres,Conesa, Juan A.,Font, Rafael,Sidhu, Sukh
, p. 2953 - 2958 (2007/10/03)
The limitations facing land filling and recycling and the planned ban on sea disposal of sludge leads to the expectation that the role of sludge incineration will increase in the future. The expected increase in sludge incineration will also increase scrutiny of the main drawback to sewage sludge incineration-the formation of hazardous air pollutants (HAPs). Despite the extensive body of knowledge available on sewage sludge combustion, very few studies have been conducted on the formation of HAPs during sludge combustion. In this work, the interactions between sewage sludge pyrolysis products and sludge ash were investigated using a dual chamber flow reactor system and a horizontal laboratory scale reactor. The results of this study shows that sludge ash can catalyze oxidation and chlorination of organics. In the absence of HCl in the gas stream, sludge ash acts as an oxidizing catalyst, but in the presence of HCl, sludge ash acts as a chlorination catalyst producing high yields of organochloride compounds.
Formation of octachlorostyrene during the synthesis of chromium(iii) chloride
Mataruse,Yuknis,McDonald,Booth,Cleary,Twamley
, p. 69 - 74 (2007/10/03)
Octachlorostyrene has been recovered from the reaction tube, along with previously reported hexachlorobenzene, during the synthesis of CrCl3 from Cr2O3 and CCl4 at high temperature. The region in the reaction tube where the octachlorostyrene was found, namely upstream from the Cr2O3 held at 890°C, suggests that this molecule is formed at a temperature below 890°C and that it decomposes if raised to that temperature. A low gas flow was used in this experiment, allowing products to diffuse countercurrently. Copyright
Identification of surrogate compounds for the emission of PCDD/F (I-TEQ value) and evaluation of their on-line realtime detectability in flue gases of waste incineration plants by REMPI-TOFMS mass spectrometry
Blumenstock,Zimmermann,Schramm,Kettrup
, p. 507 - 518 (2007/10/03)
Correlations between products of incomplete combustion (PIC), e.g., chloroaromatic compounds, can be used to characterise the emissions from combustion processes, like municipal or hazardous waste incineration. A possible application of such relationships may be the on-line real-time monitoring of a characteristic surrogate, e.g., with Resonance-Enhanced Multiphoton Ionization-Time-of-Flight Mass Spectrometry (REMPI-TOFMS). In this paper, we report the relationships of homologues and individual congeners of chlorinated benzenes (PCBz), dibenzo-p-dioxins (PCDD), dibenzofurans (PCDF) and phenols (PCPh) to the International Toxicity Equivalent (I-TEQ) of the PCDD/F (I-TEQ value) in the flue gas and stack gas of a 22 MW hazardous waste incinerator (HWI). As the REMPI detection sensitivity is decreasing with the increase of the degree of chlorination, this study focuses on the lower chlorinated species of the compounds mentioned above. Lower chlorinated species, e.g., chlorobenzene (MCBz), 1,4-dichlorobenzene, 2,4,6-trichlorodibenzofuran or 2,4-dichlorophenol, were identified as I-TEQ surrogates in the flue gas. In contrast to the higher chlorinated phenols, the lower chlorinated phenols (degree of chlorination 4) were not reliable as surrogates in the stack gas. The identified surrogates are evaluated in terms of their detectability by REMPI-TOFMS laser mass spectrometry. The outcome is that MCBz is the best suited surrogate for (indirect) on-line measuring of the I-TEQ value in the flue gas by REMPI-TOFMS. The correlation coefficient r of the MCBz concentration to the I-TEQ in the flue gas was 0.85.
Hazardous air pollutants formation from reactions of raw meal organics in cement kilns
Sidhu, Sukh,Kasti, Nabil,Edwards, Phil,Dellinger, Barry
, p. 499 - 506 (2007/10/03)
Thermally induced chlorination, condensation, and formation reactions of raw meal organic surrogates were investigated on different types of surfaces. The System for Thermal Diagnostic Studies provided a powerful tool to study these reactions under defined reaction conditions, which were related to typical conditions in the preheater zone of cement kiln. Experiments were conducted with benzene and benzene/myristic acid (C6H6/C13H27COOH) mixtures in a quartz reactor containing different chlorinating catalysts/reagents over a temperature range of 300-500°C. Reaction products were trapped in-line and analyzed by GC-MS. A mixture of chlorides of calcium, potassium, aluminium and iron was highly effective for chlorination/condensation reactions of benzene and benzene/myristic acid mix at temperatures above 300°C. The same behavior was observed only when calcium chloride and potassium chloride were used as chlorinating catalyst/reagent. This result showed that transition metal chlorides like FeCl3 are not necessary for chlorination/condensation of organics under post-combustion conditions. Methylene chloride was the major chlorinated product followed by chloroform and various other C1, C2 and C6 chlorinated products. Yields of chlorinated aliphatics were highest at 400°C for both benzene and benzene/myristic acid mix. C6 products were mainly mono- to hexa-chlorinated benzenes with trace amounts of chlorinated phenols. The major chlorinated products observed in this study (i.e., methylene chloride, chloroform, chloroethanes and monochlorobenzene) were also present as major chlorinated hydrocarbons in the cement kiln field emission data.
