Chlorinated alkanes and alkenes

Brown et al. (1998), using whole needles of Pirns sylvestris (Scots pine), obtained a QSAR with very different coefficients for a very small series of chlorinated alkanes and alkenes ... 

Wang FI, Kuo ML, Shun CT, et al. Chronic toxicity of a mixture of chlorinated alkanes and alkenes in ICR mice. J Toxicol Environ Health 2002 65(3-4) 279-91. 

Reductions Microbial and mammalian nitroreductase reduces nitro compounds to amines. Chlorinated alkanes and alkenes are common contaminants in ground water and chlorinated aromatics, PCBs, organochlorine pesticides, are often detected in soils and sediments and it has been of interest to evaluate the potential for these compounds to be metabolized. A number of microorganisms are able to dechlorinate both halogenated aliphatic and aromatic compounds in a reduction reaction." It has been observed that the more highly chlorinated congeners are more reactive in these systems in contrast to the response in oxidative dechlorinations. 

This study was undertaken to test the ability of our previous molecular connectivity models to accurately predict the soil sorption coefficients, bioconcentration factors, and acute toxicities in fish of polycyclic aromatic hydrocarbons (PAHs), alkylbenzenes, alkenylbenzenes, chlorobenzenes, polychlorinated biphenyls, chlorinated alkanes and alkenes, heterocyclic arid substituted PAHs, and halogenated phenols. Tests performed on large groups of such compounds clearly demonstrate that these simple nonempirical models accurately predict the soil sorption coefficients, bioconcentration factors, and acute toxicities in fish of the above compounds. Moreover, they outperform traditional empirical models based on 1-octanol/ water partition coefficients or water solubilities in accuracy, speed, and range of applicability. These results show that the molecular connectivity models are a very accurate predictive tool for the soil sorption coefficients, bioconcentration factors, and acute toxicities in fish of a wide range of organic chemicals and that it can be confidently used to rank potentially hazardous chemicals and thus to create a priority testing list. ... 

TABLE 1 Comparison of observed and predicted (equation 6) soil sorption coefficients (KQn )of chlorobenzenes, PAHs, alkylbenzenes, chlorinated alkanes and alkenes, heterocyclic-PAHs, substituted-PAHs, and chlorophenols, and theirfirst-order molecular connectivity indices Cx)-... 

TABLE 6 Comparison of observed and predicted (equation 8) acute toxicities (96-hr LC50) of chlorinated alkanes and alkenes in fathead minnows and their zero-order molecular connectivity indices (°x)-... 

Interest in the bioremediation of chlorinated solvents is widespread. It is impractical to consider all the excellent efforts underway. An example will be given for both a chlorinated alkane and a chlorinated alkene. Both compounds, dichloromethane and trichloroethylene, are commonly used industrial solvents and degreasers that are important soil and water pollutants. 

ELUmo is a measure of the ability of a compound to accept electrons (i.e., to act as an electrophile or undergo reduction). The above correlations show a decrease in ELUMO as the number of chlorines increases. As ELUM0 decreases, the ability of a compound to behave as an electrophile increases however, properties that increase stability increase LUMO energy and decrease reactivity. For example, between two-carbon alkanes and alkenes, r = -0.5104 and r = -0.9948, respectively. These data agree with Richard and Hunter (1996) in regard to the stability of alkanes over alkenes. 

Alkanes and Alkenes Radical Initiated Chlorination of 1-Chlorobutane... 

A a) In what way do alkanes and alkenes react with chlorine gas Give equations using the first member of each series as the example. (6)... 

Chlorocarbons are a particular concern owing to their persistence in the environment and the lack of metabolic cleansing pathways in organisms and high fat solubility. Consequently, these substances bioaccumulate in the food chain, with unclear or deleterious effects on health and environmental quality. Chlorocarbons are considered separate from pesticides (see separate discussion) in this discussion and are chlorinated benzenes or phenols and chlorinated alkanes or alkenes. Volatile compounds in water were purged for determination by IMS with a corona discharge (CD) ion source. Chlorobenzene at 3 to 30 mg/L was determined in 5 min, which was considered suitable for on-site measurements at a restoration site. 

B. Heinrichs, P. Delhez, J.-P. Schoebrechts, and J.-P. Pirard, Pd-Ag/Si02 Sol-Gel Catalysts Designed for Selective Conversion of Chlorinated Alkanes into Alkenes, Stud. Surf. Sci. Catal., 118, pp. 707-16, 1998. 

A number of chlorinated hydrocarbons arise during reactions of alkanes and alkenes with various chlorinated compounds, or by degradation of other chlorinated compounds. For example, as components of acid protein hydrolysates by traditional technology (hydrolysis with hydrochloric acid), 1,2-dichloropropane and 1,3-dichloropropane (see Section 12.2.4.1) are produced, the precursors of which are residual triacylglycerols found in oilseed meals. 

Chlorinated, Brominated, and Iodinated Alkanes, Alkenes, and Alkanoates... 

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