Biphenyl, reduction

Reduction potentials of silyl-substituted biphenyls have also been investigated [69], The half wave potentials of 4-trimethylsilylbiphenyl and 4,4 -bis(trimethylsilyl)biphenyl are slightly less negative than that of unsubstituted biphenyl. Reduction potentials of nitrophenylsilanes are less negative than that of nitrobenzene, but the difference is usually not so large [70],... 

Organic Chloride Content—by distillation and sodium biphenyl reduction or microcoulometry (ASTM Test Method D4929, Determination of Organic Chloride Content in Crude Oil). ... 

These test methods cover the determination of organic chloride (above 1 xg/g organically-bound chlorine) in crude oils, using either distillation and sodium biphenyl reduction or distillation and microcoulometry. 

Test Method A covers the determination of organic chloride in the washed naphtha fraction of crude oil by sodium biphenyl reduction followed by potentiometric titration. 

TEST METHOD A—SODIUM BIPHENYL REDUCTION AND POTENTIOMETRY... 

Interest in the synthesis of 19-norsteroids as orally active progestins prompted efforts to remove the C19 angular methyl substituent of readily available steroid precursors. Industrial applications include the direct conversion of androsta-l,4-diene-3,17-dione [897-06-3] (92) to estrone [53-16-7] (26) by thermolysis in mineral oil at about 500°C (136), and reductive elimination of the angular methyl group of the 17-ketal of the dione [2398-63-2] (93) with lithium biphenyl radical anion to form the 17-ketal of estrone [900-83-4] (94) (137). 

Promotes pollution prevention, the use of safer chemicals through regulatory and vohmtaiy efforts, risk reduction so as to minimize exposure to existing substances such as lead, asbestos, dioxin, and polychlorinated biphenyls, promotes the public understanding of risks by providing understandable, accessible and complete information on chemical risks. 

Electrochemical reduction of pentatluoronitrobenzene produces an intermediate radical anion that couples at position 4 to form the corresponding biphenyl along with hydroxy derivatives from subsequent nucleophilic substitution meta to the nitio groups [44] (equation 34) Similar reduction of halopyridines such as pen-tafluoropyridine leads mainly to 4,4 bipyridyls [45] (equation 35)... 

Chlorinated dibenzo ip-dioxins are contaminants of phenol-based pesticides and may enter the environment where they are subject to the action of sunlight. Rate measurements showed that 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is more rapidly photolyzed in methanol than octachlorodi-benzo-p-dioxin. Initially TCDD yields 2,3,7-trichlorodiben-zo-p-dioxin, and subsequent reductive dechlorination is accompanied by ring fission. Pure dibenzo-p-dioxin gave polymeric material and some 2,2 -dihydroxybiphenyl on irradiation. Riboflavin-sensitized photolysis of the potential precursors of dioxins, 2,4-dichlorophenol and 2,4,5-trichloro-phenol, in water gave no detectable dioxins. The products identified were chlorinated phenoxyphenols and dihydroxy-biphenyls. In contrast, aqueous alkaline solutions of purified pentachlorophenol gave traces of octachlorodibenzo-p-dioxin on irradiation. 

Bedard DL, H van Dort, KA Deweerd (1998) Brominated biphenyls prime extensive microbial reductive deha-logenation of Arochlor 1260 in Housatonic River sediment. Appl Environ Microbiol 64 1786-1795. 

Morris PJ, JF Quensen III, JM Tiedje, SA Boyd (1992) Reductive debromination of the commercial polybro-minated biphenyl mixture Firemaster BP6 by anaerobic microorganisms from sediments. Appl Environ Microbiol 58 3249-3256. 

Wu Q, DL Bedard, J Wiegel (1997a) Effect of incubation temperature on the route of microbial reductive dechlorination of 2,3,4,6-tetrachlorobiphenyl in polychlorinated biphenyl (PCB)-contaminated and PCB-free freshwater sediments. Appl Environ Microbiol 63 2836-2843. 

Bedard DL, HM van Dort (1998) Complete reductive dehalogenation of brominated biphenyls by anaerobic microorganisms in sediment. Appl Environ Microbiol 64 940-947. 

Bedard DL, JE Quensen III (1995) Microbial reductive dechlorination of polychlorinated biphenyls. In Microbial transformation and Degradation of Toxic Organic Chemicals (Eds LY Yonng, CE Cemiglia), pp. 127-216. Wiley-Liss, New York. 

Fagervold SK, JEM Watts, HD May, KR Sowers (2005) Sequential reductive dechlorination of meta-chlorinated polychlorinated biphenyl congeners in sediment microcosms by two different types of Chloroflexi phylotypes. Appl Environ Microbiol 71 8085-8090. 

Wu Q, JEM Watts, KR Sowers, HD May (2002) Identification of a bacterium that specifically catalyzes the reductive dechlorination of polychlorinated biphenyls with doubly flanked chlorines. Appl Environ Microbiol 68 807-812. 

Drenzer NJ, T1 Eglinton, CO Wirsen, HD May, Q Wu, KR Sowers, CM Reddy (2001) The absence and application of stable carbon isotope fractionation during the reductive dechlorination of polychlorinated biphenyls. Environ Sci Technol 35 3310-3313. 

Morris PJ, JF Quensen, JM Tiedje, SA Boyd (1993) An assessment of the reductive debromination of polybro-minated biphenyls in the Pine River reservoir. Environ Sci Technol 27 1580-1586. 

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