1782-00-9Relevant academic research and scientific papers
Photocatalytic degradation of lindane by polyoxometalates: Intermediates and mechanistic aspects
Antonaraki,Triantis,Papaconstantinou,Hiskia
experimental part, p. 119 - 124 (2010/08/22)
The photocatalytic degradation of lindane (γ-1,2,3,4,5,6-hexachlorocyclohexane) has been studied in the presence of the polyoxometalate PW12O403- in aqueous solutions. Lindane is fully decomposed to CO2, Cl- and H2O, while a great variety of intermediates has been detected using GC-MS, including aromatic compounds (dichlorophenol, trichlorophenols, tetrachlorophenol, hexachlorobenzene, di- and trichloro-benzenodiol), non-aromatic cyclic compounds (penta-, tetrachlorocyclohexene, heptachlorocyclohexane), aliphatic compounds (tetrachloroethane) and condensation products (polychlorinated biphenyls). The number and nature of the intermediates implies that the mechanism of decomposition of lindane is based on both oxidative and reductive processes. Common intermediates have been reported during photolysis of lindane in the presence of titanium dioxide. A similar overall mechanism of polyoxometalates and TiO2 photocatalysis through the formation of common reactive species is suggested.
Ultraviolet Light Induced Dechlorination of Vicinal Polychlorocyclohexanes with Triethylamine
Takagi, Katsuhiko,Ogata, Yoshiro
, p. 1966 - 1970 (2007/10/02)
Photochemical dechlorination of trans- and cis-1,2-dichlorocyclohexanes (t-and c-DCC) in the presence of triethylamine (TEA) results in predominant dechlorination to form cyclohexene, where higher reactivity of the trans isomer over that of the cis (Φt-DCC/Φc-DCC = 4.8) is observed.Four stereoisomers of 1,2,3,4,5,6-hexachlorocyclohexanes, i.e., benzene hexaclorides (BHCs), were similarly dechlorinated to give their stereoselective benzene tetrachlorides (BTC), which mainly lose two adjacent chlorine atoms with a trans configuration to each other among the six chlorines available in BHC.Quantum efficiencies for the dechlorination of the four isomers α-, β-, γ-, and δ-BHC are 0.072, 0.060, 0.19, and 0,11, respectively, which correlate with their reduction potentials, implying that the reaction may be initiated by an electron transfer from TEA to BHC.
Radiation- and Photo-Induced Degradation of Five Isomers of 1,2,3,4,5,6-Hexachlorocyclohexane
Hamada, Masayuki,Kawano, Eiko,Kawamura, Shunichi,Shiro, Motoo
, p. 659 - 666 (2007/10/02)
γ-Isomer of 1,2,3,4,5,6-hexachlorocyclohexane (BHC) showed greater decomposition on γ or UV irradiation of five isomers of BHC in crystalline state or in 2-propanol solution.The α- and δ-isomer of BHC and known 1a,2a,3e,4e,5e-pentachlorocyclohexane were separated from the irradiation product of crystalline γ-BHC.Four compounds were isolated from the irradiation product of γ-BHC in 2-propanol Two compounds were tetrachlorocyclohexenes (C6H6Cl4): γ-isomer (mp 86-87 deg C) and ε-isomer (mp 99-100 deg C).The other two were isomers of pentachlorocyclohexane (C6H7Cl5).One of them (mp 78-8.5 deg C) was consistent with known meso-1e,2a,3a,4a,5e isomer.The molecular structure of the other (mp 75 deg C) established by X-ray crystal structure analysis was 1α,2α,3α,4β,5α configuration or 1e 2a 3e 4e 5e conformation of Cl atoms.A reaction mechanism was proposed that included a radical chain reaction and chlorine atom migration.
