Chlorine physicochemical properties

However, the physicochemical properties of nitrogen chloride give no grounds for the explanation of its stability under melt electrolysis conditions. The possibility of the formation of a chlorine derivative of carbamide according to the scheme ... 

All PCDD/F isomers are solids with high melting points, but low vapor pressure and low solubihty in water. The high octanol-water coefficients are an indication of the observed bioaccumulative behavior in plants and animals for these compounds. Detailed environmentally important physicochemical properties can be found in the literature. All higher chlorinated compounds are very persistent in the environment with half-lives of 5-10 years photolysis with sunlight is the only degradation process in the environment. 

CDDs are characterized by low water solubilities and high lipophilicities. Kow values range from 104 to 1012 for MCDD through OCDD, with Kow values increasing relative to increasing chlorination (Table 3-2). Because of these physicochemical properties, CDDs are expected to adsorb to bedded and suspended sediments and to bioaccumulate in aquatic organisms. 

Table 7. Physicochemical properties of some silicone compounds chlorine derivatives of unsaturated ...

Similarly to vinyltrichlorosilane, vinylmethyldichlorosilane and methylthyenildichlorosilane, HTC is used to produce allyltrichlorosilane, thyenil-trichlorosilane, vinylethyldichlorosilane, allylmethyldichlorosilane, vinyl-phenyldichlorosilane and other chlorine-containing silicone monomers with organic radicals attached to the silicon atom. Table 7 lists the physicochemical properties of some chlorine derivatives of unsaturated silicone compounds. 

Table 9. Physicochemical properties of chlorinated methyl-, phenyl- and methyl-phenylchlorosilanes...

The isomers of AtC6H4CF3 have been synthesized by the same team via nucleophilic chlorine replacement from the C1C6H4CF3 isomers. The yields (30-45%) are much lower than in the case of chlorine replacement in chlorobenzene, but no isomerization of the original compound could be observed thereby allowing determination by GLC of some physicochemical properties (see Section IV) of the products obtained for the first time28. 

Secondly, following emission, the relative partitioning between air and dust for a given compound will be influenced strongly by its physicochemical properties. Broadly, more volatile pollutants, like lower chlorinated PCBs, will partition preferentially to air, while those with lower vapour pressures, like BDE-209, HBCDs, and TBBP-A, will partition preferentially to dust (Abdallah, Harrad, and Covaci, 2008 Abdallah et al., 2008 Harrad, Hazrati, and Ibarra, 2006 Harrad et al., 2008b). 

If other, nonisotopic chlorination agents and carriers can also serve the purpose, then to what degree may their physicochemical properties differ from those of the compound of interest ... 

One possible explanation for this trend Is that bound PCB s derived from an atmospheric source and were associated with soot particles. Several physicochemical properties of PCB s could favor the generation of atmospheric assemblages enriched In less chlorinated Isomers laboratory studies of PCB s demonstrate that there Is a trend toward higher vapor pressure with decreasing chlorine content (37) and that photodecomposition selectively destroys higher... 

The existing information regarding distribution of PCBs in humans is limited. Nevertheless, based on experimental data obtained in animals (see Section 3.4.2.2) and the known physicochemical properties of PCBs, it is reasonable to assume that the lipid soluble PCBs, once cleared from the bloodstream, will accumulate in highest concentration in fatty tissues. Initially, however, PCBs could accumulate in the liver due to its high blood perfusion rate. The availabiUty of PCBs for retention in fatty tissues is intimately linked to metaboUsm (see Section 3.4.3) therefore, it would be expected that the higher chlorinated PCBs would persist for longer periods of time solubiUzed in fatty tissues. 

Sediment concentration data of major groups of organic contaminants -aliphatic and aromatic hydrocarbons, chlorinated pesticides, phenols, polychlorinated biphenyls and -dibenzodioxins - are summarized in Table 2-5 (the book by Moore Ramamoorthy contains information on physicochemical properties, production, uses and discharges, and on toxicity). 

Fig. 2.34. Isosteric replacement of chlorine in thiazide diuretics. Comparison of physicochemical properties of the substituents. ...

The simplest form of a Free Wilson analysis is presented in eq. 192 [22], which describes the antibacterial activities of phenol and isomeric chlorophenols (51, R = H, Cl one to five chlorine atoms) vs. Staphylococcus aureus at least the linearity of the structure-activity relationship can be derived from eq. 192 on the other hand, although most probably lipophilicity is responsible for the variance in the biological activities, no Hansch equation can be derived, because each other physicochemical property of the chlorine atom will give identical results. 

As chlorinated fatty acids in lipid extracts cannot be separated from non-chlorinated matrix by routine cleanup techniques, because of the similarity in their chemical and physicochemical properties, chromatographic elution is often the sole effective means of separation for identification and quantitation of chlorinated fatty acids. As chlorinated fatty acids are present in biota extracts at trace levels, it is critical to have a detector that is highly specific for... 

Structural analysis of traces of chlorinated fatty acids in biota often requires prior enrichment or cleanup. Analysis of chlorinated pesticides and polychlorinated biphenyls can be facilitated by a simple cleanup procedure such as the sulfuric acid treatment or gel permeation chromatography with a single cutoff point to eliminate high molecular weight lipids. Owing to the similarity in chemical and physicochemical properties between analytes (chlorinated fatty acids) and matrix compounds (non-chlorinated fatty acids), conventional cleanup procedures are not applicable for the... 

Pentachlorobenzene is part of a small class of chlorobenzenes consisting of 12 different isomers. These isomers display a range of physicochemical properties that are specifically related to the degree of chlorination and account for the broad range of application for chlorinated benzenes in both home and industry (Peattie and Lindsay 1984). Thomas et al. (1998) reported that pentachlorobenzene significantly promotes the growth of glutathione S-transferase it foci in the medium-term fiver foci bioassay. 

---