Halogen compounds, organic importance

The most important of the halogenated derivatives of acetic acid is chloroacetic acid. Fluorine, chlorine, bromine, and iodine derivatives are all known, as are mixed halogenated acids. For a discussion of the fluorine derivatives see Fluorine compounds, organic. 

Of the halogen compounds of carbon, the most important is CC14 (b.p. 77 °C) that is widely used as a solvent. However, the fully halogenated compounds are usually considered as derivatives of methane, so they are usually considered as "organic" in origin. Carbon tetrachloride is produced by the reaction... 

Detectors range from the universal, but less sensitive, to the very sensitive but limited to a particular class of compounds. The thermal conductivity detector (TCD) is the least sensitive but responds to all classes of compounds. Another common detector is the flame ionization detector (FID), which is very sensitive but can only detect organic compounds. Another common and very sensitive detector is called electron capture. This detector is particularly sensitive to halogenated compounds, which can be particularly important when analyzing pollutants such as dichlorodiphenyltrichloroethane (DDT) and polychlorobiphenyl (PCB) compounds. Chapter 13 provides more specific information about chromatographic methods applied to soil analysis. 

During the past ten to fifteen years, considerable progress has been made with transition metal-mediated organic syntheses. Two important new methods are available for the coupling of acetylenes with the halogen compounds mentioned above. 

Figure 14.4 Selection of environmentally relevant redox couples including organic pollutants such as nitroaromatic and halogenated compounds, as well as examples of electron transfer mediators and important bulk reductants. The values given represent reduction potentials at pH 7 at equal (except otherwise indicated) concentrations of the redox partners but at environmental con-centrations of the major anions involved ...

Several commercially important photochemical processes involve the reaction of a halogenated compound with an organic substrate, and although it is the non-organic component that is excited, it is appropriate to describe them in this section. 

The most important results that throw light on the Si-Si bond are summarized in this review. It deals first with the hydrogen and halogen compounds having Si—Si bonds, describes the preparation and properties of organic substituted disilanes and oligosilanes, and discusses the physicochemical properties of the Si—Si bond. 

Halomethanes are small they are the simplest organic halogen compounds, and yet, as shown in Table 3, barely half of their total number66 has been studied by PES. They have much technological (refrigerants, propellants) and ecological (ozone layer) importance. The main reason for the ca 50% roster is the instability of many halomethanes (e.g. CF2I2)67. 

Introduction of halogen into organic compounds is a very important reaction in... 

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