67471-27-6Relevant articles and documents
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.
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.
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.
