24478-72-6Relevant articles and documents
Superacid-promoted synthesis of polychlorinated dibenzofurans
Qarah, Ahmad,Gasonoo, Makafui,Do, Dat,Klumpp, Douglas A.
, p. 3711 - 3714 (2016)
Polychlorinated dibenzofurans have been prepared in one step by the condensations of o-chloranil with arenes in triflic acid. A mechanism is proposed involving formation of a monoprotonated quinone (carboxonium ion), electrophilic attack at the arene, and cyclization of a carbocation intermediate. The chemistry is further examined by spectroscopic and theoretical studies.
Biosorption of 1,2,3,4-tetrachlorodibenzo-p-dioxin and polychlorinated dibenzofurans by Bacillus pumilus
Hong, Hyo-Bong,Hwang, Seok-Hwan,Chang, Yoon-Seok
, p. 349 - 353 (2000)
Microbial adsorption of 1,2,3,4-tetrachlorodibenzo-p-dioxin (1,2,3,4-TCDD) and various polychlorinated dibenzofurans (PCDFs) was investigated in an effort to determine the significance of microorganisms as potential agents in transferring the molecules in the environment. The microorganisms used in this study were cultivated under low nutrient conditions for 2 months. The increase and decrease of 1,2,3,4-TCDD and PCDFs in the samples were measured by GC/MS. The peak of dibenzofuran (DBF), added as an internal standard, was compared with the peaks of 1,2,3,4-TCDD and PCDFs. The results showed that the dead biomass of microorganisms could remove these molecules from the medium more effectively than live cells. The subsequent studies suggested that the removal of the molecules be concerned with the unknown biocompound(s) of which secretion is pronounced at high temperature. UV-VIS spectrometry was used to monitor the change in the concentration of biocompound(s).
Natural formation of chlorinated phenols, dibenzo-p-dioxins, and dibenzofurans in soil of a Douglas fir forest
Hoekstra, Eddo J.,De Weerd, Henk,De Leer, Ed W. B.,Brinkman, Udo A.Th.
, p. 2543 - 2549 (2007/10/03)
The natural formation of 4-MCP, 24/25- and 26-DCP, and 245-TrCP was detected in four selected areas of a rural Douglas fir forest where the humic layer was spiked in situ with a solution of Na37Cl and covered by an enclosure, after 1 year of incubation. Chlorinated phenols (CP) can be formed naturally from organic matter and inorganic chloride by either de novo synthesis or chloroperoxidase (CPO)-catalyzed chlorination. The natural CP congeners were found to be present in high concentrations in soil compared to the other congeners, except for 245-TrCP which was present in a relatively low concentration. This study did not reveal which source, natural or anthropogenic, caused the observed concentrations. Some 20 chlorinated dibenzo-p-dioxins and dibenzofurans (CDD/F) were found to be formed naturally in soil of the Douglas fir forest; the formation of three 2,3,7,8-substituted congeners, 2378-TeCDD, 12378-PeCDD, and 123789-HxCDD, deserves special attention. A formation mechanism has been proposed which starts from naturally formed CP congeners and which probably involves peroxidase mediation. Chlorination of CDD/F congeners by the CPO-mediated reaction cannot be ruled out, but seems to be less likely due to the absence of several predicted congeners. The natural formation of 4-MCP, 24/25- and 26-DCP, and 245-TrCP was detected in four selected areas of a rural Douglas fir forest where the humic layer was spiked in situ with a solution of Na37Cl and covered by an enclosure, after 1 year of incubation. Chlorinated phenols (CP) can be formed naturally from organic matter and inorganic chloride by either de novo synthesis or chloroperoxidase (CPO)-catalyzed chlorination. The natural CP congeners were found to be present in high concentrations in soil compared to the other congeners, except for 245-TrCP which was present in a relatively low concentration. This study did not reveal which source, natural or anthropogenic, caused the observed concentrations. Some 20 chlorinated dibenzo-p-dioxins and dibenzofurans (CDD/F) were found to be formed naturally in soil of the Douglas fir forest; the formation of three 2,3,7,8-substituted congeners, 2378-TeCDD, 12378-PeCDD, and 123789-HxCDD, deserves special attention. A formation mechanism has been proposed which starts from naturally formed CP congeners and which probably involves peroxidase mediation. Chlorination of CDD/F congeners by the CPO-mediated reaction cannot be ruled out, but seems to be less likely due to the absence of several predicted congeners.