Alkanes, addition halogenation

Alkenes undergo addition reactions with hydrogen to form alkanes, with halogens to form dihaloalkanes, with hydrogen halides to form monohaloalkanes and with water to form alcohols. For example ... 

The resting state (MMOoxd) is reduced back to the diferrous form to close the cycle. In addition to methane, many other substrates react with MMO. These include long-chain alkanes, alkenes, halogenated and other substituted alkanes, alkynes, sulfides, and others. 

Physical Properties of Haloalkanes Preparation of Haloalkanes by Halogenation of Alkanes Mechanism of Halogenation of Alkanes Allylic Halogenation Radical Autoxidation Radical Addition of HBr to Alkenes... 

In contrast to the free radical substitution observed when halogens react with alkanes halogens normally react with alkenes by electrophilic addition... 

This method is also used with alcohols of the stmcture Cl(CH2) OH (114). HaloaLkyl chlorosulfates are likewise obtained from the reaction of halogenated alkanes with sulfur trioxide or from the chlorination of cycHc sulfites (115,116). Chlorosilanes form chlorosulfate esters when treated with sulfur trioxide or chlorosulfuric acid (117). Another approach to halosulfates is based on the addition of chlorosulfuric or fluorosulfuric acid to alkenes in nonpolar solvents (118). 

Their physieal properties are essentially those of the alkanes. It is the unsaturated linkages that dominate the ehemistry and the main reaetion is one of addition (e.g. hydrogen, halogen, and hydrogen halides) aeross the double bond to produee saturated eompounds. This reaetivity is utilized in the manufaeture of long-ehain polymers, e.g. polyethylene and polypropylene. 

Generally, the addition of chlonne or bromine to tnfluoroacetonitrile leads to a mixture of partially halogenated imines, amines and azo alkanes [270, 271] In special cases, such as the HgF2-mediated addition of bromine, N,N dihaloper-fluoro-2-alkylamines can be obtained in good yields [272]... 

As discussed in Chapter 6, group additivity approaches have been developed for estimating the rate constants for the reactions of a variety of species such as OH with organics. DeMore (1996) has applied a similar approach for estimating the rate constants for the reaction of OH with halogenated alkanes. The rate constant per hydrogen atom at 298 K is calculated using Eq. (D) ... 

Haloform reaction, 237, 296 Halogenation alkanes, 300, 323 alkenes, 179,186, 313 benzene, 138,316 ketones, 295 Hammett equation, 362 additional parameters, 374, 388, 395 derivation of, 362 deviations from, 375 empirical nature of, 395 implications of, 394 reaction pathway, and, 375 solvent effects and, 388 spectroscopic correlations, 392 standard reaction for, 362, 395 steric effects and, 361, 383 thermodynamic implications of, 394 Hammett plots, 359 change in rate-limiting step and, 383 change in reaction pathway and, 378... 

The production of nitromethane and its use as a solvent, fuel additive, stabilizer for halogenated alkanes, and intermediate may result in the release of nitromethane into the environment, principally into the atmosphere. Human exposure to nitromethane may additionally occur via dermal contact and accidental ingestion of methanol-nitromethane fuel mixtures (Kaiffer et al., 1972 Sandyk Gillman, 1984 Dayal et al., 1989 De Leacy et al., 1989 Lundberg, 1989 National Toxicology Program, 1997 Mullins Hammett-Stabler, 1998). 

Other methods for the preparation of alkyl halides are electrophilic addition of hydrogen halides (HX) to alkenes (see Section 5.3.1) and free radical halogenation of alkanes (see Section 5.2). 

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