Haloorganics

The effects of occupational exposure to lindane have been investigated extensively (96—100). These studies indicated that occupational exposure to lindane resulted in increased body burdens of this chemical however, toxic effects associated with these exposures were minimal and no central nervous system disorders were observed. This is in contrast to the polyneuropathies that are often observed after exposure to other haloorganic solvents. 

Inmost instances, a haloorganic subject to either SN2 displacement reaction or SN1 substitution is heated at reflux with the trivalent phosphorus ester with the concomitant formation of the valence-expanded organophosphorus compound and haloorganic by-product, as illustrated with an example in Equation 3.1. 

The Curie Point flush evaporation-pyrolysis gas chromatography-mass spectrometric method [27] described in section 2.2.1.2 for the analysis of aliphatic hydrocarbons in soils has also been applied to the determination of haloorganic compounds such as di- and trichlorobenzenes. 

The flash evaporation pyrolysis gas chromatography method [16] as described in section 11.1.4 for the determination of polycyclic aromatic hydrocarbons, haloorganics, aliphatic hydrocarbons, heteroaromatics, elemental sulphur and pyrolysis products of synthetic polymers in soils has also been applied to non-saline sediments. 

Golovanova, Yu.G. and Kolesov, V.P. Enthalpies of melting, melting temperatures, and cryoscopic constants of some haloorganic compounds, Vestn. Mosk Univ, Ser. 2 Khlm, 25(3) 244-248, 1984. 

A long series on the kinetics and mechanism of the unimolecular heterolysis of commercial haloorganic compounds has continued in a study of the effect of bromide salts and lithium perchlorate on the ionization rate of benzhydryl bromide in y-butyrolactone and acetone.122 The verdazyl indicator method was applied. The nature of special and normal salt effects has also been discussed.123... 

Two previous reviews on radiolysis of haloorganic compounds were published in this series n 2. Consequently, this review is only for the period starting in 1983. 

Pyridinyl radicals react with haloorganic compotinds at ratra that are very sensitive to the strength of the halogen-carbon bond. Both atom-transfer and electron-transfer mechanisms for the reaction have been detected, with the latter exhibiting a large response to solvent polarity change and to variations in the electron affinity of the organic halide. 

Gould JP, Ramsey RE, Giabani M, et al. 1983. Formation of volatile haloorganic compounds in the chlorination of municipal landfill leachates. Water Chlorination, Environmental Impact and Health Effects 4 525-539. 

The distinction in previous sections of electroanalysis, inorganic electrochemistry (particularly metal systems), and electroorganic synthesis leaves out a number of other electrochemical systems. Ultrasound has been applied to many of these, to interesting effect, and this section concerns a number of such systems. There is, of course, overlap in any attempt at compartmentalization, and here some studies on batteries, electrochemiluminescence, and micellar systems could be considered as contributing to electroanalysis, while other multiphase electrolyses might be considered as electrosynthesis. In addition, most multiphase electrolysis is directed to the destruction of haloorganics and is aimed at waste treatment. There are also one-off applications of ultrasound in electrochemistry, which are collected at the end of this section. 

R628 H. F. Schroder, Possibilities for Determining Individual Haloorganic Substances , ATV-DVWK-Schriftenr., 2000,18, 159... 

The reactor outlet airstream eontained most of the diehloromethane and carbon tetrachloride present in the inlet stream. This result was expeeted, as single carbon haloorganics do not easily photo-oxidize (Jacoby et. al, 1994). Nearly all of the 1,1-dichloroethene and eis-l,2-diehloroethane were destroyed (destruction efficiencies of 97.3% and 99.1% respectively). This too was expected, as dichlorinated ethanes and ethenes photooxidize almost as rapidly as TCE. 

A class of peroxidases specializes in the (per)oxidation of halides (d , Br , T but not FO, thus creating reactive halogenating species (such as hypohalite), which in turn form haloorganic compounds [1320, 1321]. These reactions are described in Sect. 2.7.1. 

ABSTRACT Photooxidation of many organic compounds (e.g., haloorganics, surfactants, pesticides, etc.) dissolved in aqueous systems over illuminated semiconductor materials (e.g., Ti02> leads in almost all cases to quantitative formation of carbon dioxide and, eventually, of inorganic acids (e.g., HCl from chlorinated compounds). The possible application in the treatment of both waste waters and drinking water is illustrated. 

Naturally occurring haloorganics have long attracted attention, owing to their medicinal properties. The synthesis of haloaromatic compounds typically includes electrophilic attack of activated aromatic rings. 

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