Halogenation aromatic. Table

Aliphatic Halogen Compounds, Table III, 42 Aromatic Halogen Compounds, Table IV, 28. Aliphatic Ethers, Table III, 60. 

Table 3. Halogenated aromatics transformed by Pd catalysts in aqueous solution...

Table 2-11. Toxicity Equivalency Factors (TEFs) for Halogenated Aromatic Hydrocarbons... 

Table 1 Multiplicity of halogenated aromatic compounds number of isomers and congeners3...

Table 10.10. Aliphatic halogen compounds Table 10.11. Aromatic halogen compounds Table 10.12. Aliphatic ethers...

As shown in Table I, photoreactions of certain halogenated aromatic compounds and conjugated dienes are very rapid with full exposure to solar radiation. Field studies of Crossland and Wolff (10) showed that direct photoreaction of pentachlorophenol was its dominant fate in selected ponds in southern England (Figure 1). 

Most of the research on xenobiotic receptors has been conducted in mammalian systems. These studies have identified three families of proteins as having important roles in regulating the response to xenobiotic chemicals (Table 1). The aryl hydrocarbon receptor (AHR), a member of the basic helix-loop-helix Per-ARNT-Sim (bHLH-PAS) family of transcription factors, is well known for its role in the altered gene expression and toxicity elicited by chlorinated dioxins and related planar halogenated aromatic hydrocarbons (PHAHs) as well as certain polynuclear aromatic hydrocarbons (PAHs)114 188 244. Several members of the nuclear/steroid... 

Arylation of amines in combinatorial synthesis has been achieved by nucleophilic aromatic substitution or by metal-catalyzed amine/halogen exchange (Table 3.5). 

In addition to the local contamination numerous substances were detected within the nonextractable fraction, that are common riverine contaminants including e.g. phosphates, nitro compounds, UV-protectors, pesticides, fragrances, organotin compounds and halogenated aromatics (see Table 2). 

In the following sections the quantified occurrence of specific riverine contaminants including their mode of association is discussed in detail for the Teltow Canal sediments investigated. The contaminants determined were attributed to halogenated aromatics, nitro compounds, plasticizers, technical additives and fragrances. The chemical structures are illustrated in Figure 1 and all quantitative results are presented in Tables 3 to 5. 

Dioxins are chemical contaminants produced during the synthesis of chlorophenols and certain other halogenated aromatic hydrocarbons. There are 75 dioxin isomers of which 2,3,7,8 tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) is the most toxic in animal studies (1 ). Table I illustrates some major substances contaminated with isomers of dioxin. These manufactured products include 2,4,5-trichloro-phenol (TCP) and its derivatives, such as 2,4,5-trichlorophenoxy-acetic acid (2,4,5-T), which are contaminated with 2,3,7,8-TCDD, as well as pentachlorophenol, which is contaminated with hexa-, hepta-, and octachlorinated isomers of dioxin. 

We know from the chemistry of halogenated aromatic ring systems that fluorine can backbond to the aromatic. -electron system using one of its lone pairs. This ability is far less pronounced in chlorine, and entirely absent in the higher homo-logues bromine and iodine. The data in Table 2.5 corroborates this assumption for the interaction between phosphorus and halides. 

TABLE 7.5 Reduction Potentials for Hydrogenolysis of Halogenated Aromatics... 

Beside -alkanes, MN-100 also shows high affinity to halogenated hydrocarbons (Table 10.6). Chlorocarbons are retained somewhat longer than the corresponding -alkanes having approximately the same polarizability. The especially strong retention of trichloroethylene is peculiar, and is most likely caused by an additional contribution of specific interactions between the 7t-system of the adsorbate s double bond and the aromatic polymer to the total adsorption energy. In contrast, fluorocarbons are more weakly retained than -alkanes with similar polarizability most likely, the dispersion interactions of fluorocarbons with aromatic polymers are weaker. 

When the starting materials contain halogenated aromatic groups, no dehalogenation takes place. Similarly, methacrylamide and N-substituted methacrylamides give a-methylsuccinimide (see table 63). 

Fig. 8 shows a plot of vs. y y several series of related halogenated aromatic liquids on water the values of are those from publications of Harkins and co-workersand are listed in Table V. The intercept at == 0 the halogenated benzenes leads to a yQ of 34 dyn/cm. Not enough points are available for the naphtha-... 

Since relative to water for several halogenated aromatic n-alkane series could be determined, some additional surface chemical properties for these same series were calculated. The concepts of these properties and the appropriate equations had been developed by Pomerantz, Clinton and Zisman. Table V lists the initial film pressure (where ba..= Sba denotes the respective organic... 

Table 1. Production and uses of halogenated aromatic compounds (more than one ring) [22, 24, 63, 65, 81, 95, 133,141]...

Table 111,42 deals with a number of aliphatic halogen compounds together with their crystalline derivatives. Some aromatic compounds, which simulate the properties of aliphatic haUdes in some respects, are included. 

N-Benzylamides are recommended when the corresponding acid is liquid and/or water-soluble so that it cannot itself serve as a derivative. Phe benzylamides derived from the simple fatty acids or their esters are not altogether satisfactory (see Table below) those derived from most hydroxy-acids and from poly basic acids or their esters are formed in good yield and are easily purified. The esters of aromatic acids yield satisfactory derivatives but the method must compete with the equally simple process of hydrolysis and precipitation of the free acid, an obvious derivative when the acid is a solid. The procedure fails with esters of keto, sul phonic, inorganic and some halogenated aliphatic esters. 

The properties of a number of aromatic halogen compounds are collected in Table IV,28. 

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