Chlorine lengths

Properties. Physical properties of titanium tetrachloride are given ia Table 17. la the vapor phase, the titanium tetrachloride molecule is tetrahedral and has a Ti—Cl bond length of 218 pm. The regular tetrahedral coordination is retained ia the soHd, although each of the chlorines is crystaHographicaHy differeat ia the monoclinic lattice (131). 

In studies with so-called soft /V-ch1oramines, the following factors were shown to significantly influence antimicrobial activity (1) the aUphatic chain length (2) the degree of chlorination of the N atom and (3) the nature of a positive charge (11). 

As chlorination proceeds from methyl chloride to carbon tetrachloride, the length of the C—Cl bond is decreased from 0.1786 nm in the former to 0.1755 nm in the latter (3). At ca 400°C, thermal decomposition of carbon tetrachloride occurs very slowly, whereas at 900—1300°C dissociation is extensive, forming perchloroethylene and hexachloroethane and Hberating some chlorine. Subjecting the vapor to an electric arc also forms perchloroethylene and hexachloroethane, as well as hexachlorobenzene, elementary carbon, and chlorine. 

The physical and chemical properties of chlorinated paraffins are deteanined by the carbon chain length of the paraffin and the chlorine content. This is most readily seen with respect to viscosity (Fig. 1) and volatiUty (Fig. 2) increasing carbon chain length and increasing chlorine content lead to an increase in viscosity but a reduction in volatiUty. 

Paraffin carbon chain length Nominal chlorine contents, %w / w Color hazen (APHA) Viscosity, mPa-s (=cP) Density, g/mL Thermal stability, %w/wHCl Volatihty, %w/w Refractive index... 

Chlorinated paraffins are manufactured by passing pure chlorine gas into a Hquid paraffin at a temperature between 80 and 100°C depending on the chain length of the paraffin feedstock. At these temperatures chlorination occurs exothermically and cooling is necessary to maintain the temperature at around 100°C. Catalysts are not usually necessary to initiate chlorination, but some manufacturers may assist the process with ultraviolet light. Failure to control... 

Toxicity. The acute toxicity of chlotinated paraffins has been tested ia a range of animals and was found to be very low (4). A comprehensive study (5) demonstrated that the toxicity of chlotinated paraffins was related to carbon chain length and to a lesser degree chlorine content. The shorter chain-length chlotinated paraffins were more toxic than the longer chain chlotinated paraffins. 

Environmental. In general, chlorinated paraffins biodegrade the rate is determined by chlorine content and carbon chain length. Microorganisms previously acclimatized to specific chlorinated paraffins show a greater ability to degrade the compounds than nonacclimatized organisms. Mammals and fish have been shown to metabolize chlorinated paraffins (8). 

Chlorinated paraffins of average carbon chain length Cl 2 and average degree of chlorination approximately 60%... 

The isomer a-[NS(0)Cl]3 (8.15a) is a six-membered ring in the chair form with equal S-N bond lengths (1.57 A). The three chlorine atoms are... 

Two types of the homopolymer are available, the flexible and the rigid. Both types have excellent chemical and abrasion resistance. The flexible types are produced with high porosity to permit plasticizer absorption. Articles made from the rigid type are hard and cannot be stretched more than 40% of their original length. An important property of PVC is that it is self-extinguishing due to presence of the chlorine atom. 

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