Polychlorinated biphenyl analogs

Hansen LG, Welborn ME. 1977. Distribution, dilution and elimination of polychlorinated biphenyl analogs in growing swine. J Pharm Sci 66 497-501. 

The structural range of industrially important representatives of these groups is enormous, and includes chlorobenzenes (solvents), polychlorinated biphenyls (PCBs) (hydraulic and insulating fluids), and polybrominated biphenyls and diphenyl ethers (flame retardants). There is widespread concern over both the persistence and the potential toxicity of all these compounds, and sites that have become contaminated during their production represent a threat both to the environment and to human health. Pathways for the aerobic bacterial degradation of chlorobenzenes and chlorobiphe-nyls, and their brominated analogs have been discussed in Chapter 9, Part 1. 

Application of Soft Independent Method of Class Analogy (SIMCA) in Isomer Specific Analysis of Polychlorinated Biphenyls... 

Brunner, W., Sutherland, F. H. Focht, D. D. (1985). Enhanced biodegradation of polychlorinated biphenyls in soil by analog enrichment and bacterial inoculation. Journal of Environmental Quality, 14, 324-8. 

PCDTs can be formed in chemical processes analogous to those that lead to the formation of PCDFs. Condensation of chlorothiophenols instead of chloro-phenols could lead to the formation of PCDTs. Other possibilities are reactions of elemental sulfur in the presence of some metal catalysts or reactions of some reactive sulfur compounds with polychlorinated biphenyls (PCBs). 

Bitman J, Cecil HC. 1970. Estrogenic activity of DDT analogs and polychlorinated biphenyls. J Agric Food Chem 18 1108-1112. 

Polychlorinated biphenyls (PCBs) were used in this chapter as an example of a technological development that resulted in unforeseen adverse consequences to the health of the environment. Briefly smnmarize why PCBs were developed, what types of environmental problems were discovered, and what was done to mitigate the problems once they were identified. (You may need to use Internet or other sources to gather this information.) Suggest at least one characteristic of nanomaterials that should be defined in order to prevent analogous adverse consequences. 

Polybrominated diphenyl ethers (PBDEs, 12-133) are compounds structurally similar to polychlorinated biphenyls (PCBs). The numbering of209 individual PBDE congeners is analogous to the lUPAC nomenclature used for numbering PCBs (Figure 12.46). The basic skeleton is diphenyl ether with a different number and location of bromine atoms. 209 possible congeners can be derived, which... 

Likewise, Pd-[Rh(cod)Cl]2 (as well as some analogous catalysts combined with other metal particles and complexes suchas Rh-Pd(NOs)2, Ni-[Rh(cod)Cl]2 and Pt- [Rh(cod)-(PPh3)2][Pp6] ) were shown to promote hydrodechlorination of a variety of mono- and polychloroarenes. Of particular importance is the conversion of major polychlorinated environmental pollutants and toxins into non-aromatic halogen-free hydrocarbons. The hy-drodehalogenation of l,l -(2,2,2-trichloroethylidene)bis(4-chlorobenzene) (DDT), 2,2 -methylenebis( 3,4,6-trichlorophenol) (Hexachlorophene), 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), polychlorinated biphenyl (PCB), polychlorinated dibenzo[, r]dioxinc... 

J. A. Nelson, Effects of dichlorodiphenyltrichloroethane (DDT) analogs and polychlorinated biphenyl (PCB) mixtures on 17/3-[ H]estradiol binding to rat uterine receptor, Biochem. Pharmacol. 23, 447-451 (1974). 

Anaerobic dehalogenation has also been observed in aromatic ethers including polychlorinated dibenzo[l,4]dioxins (Fennell et al. 2004 Yoshida et al. 2005). The anaerobic debromination of decabromodiphenyl ether is considered here since it is analogous to the dehalogenation of polyhalogenated biphenyls. 

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