Reactive chlorine species

Albert CJ, Crowley JR, Hsu F-F, Thukkani AK, Ford DA (2001) Reactive Chlorinating Species Produced by Myeloperoxidase Target the Vinyl Ether Bond of Plasmalogens. J Biol Chem 276 23733... 

They have been divided into ROS, reactive chlorine species (RCS), and reactive nitrogen species (RNS). There are many other RS that can be represented as C, L or R depending on the nature of the compound, respectively, the carbon, lipidic, and generic radical. However, the entire body... 

The high levels of chlorine radicals CIO observed in the polar stratosphere couple with nitrogen oxides NO , resulting in the removal of reactive chlorine species by conversion into... 

Rollefson studied the competition between CO and H2 for Cl atoms produced photochemically from CI2. The variation of the total pressure at 0 °C provided an experimental measure of the competition. Rollefson found the inverse of the fractional change in H2, i.e. (AH2-l-ACO)/AH2, to be proportional to [C0]/[H2] not [CO][Cl2]/[H2]. This implies that the reactive chlorine species is the same in both HCl and COCI2 synthesis. The following reactions are suggested as being important... 

Figure 5.50. Calculated vertical distribution of reactive chlorine species at midlatitudes equinox conditions, noon values. Total amount of chlorine is assumed to be 3 ppbv.

Albert, C. J., J. R. Crowley, F. F. FIsu, A. K. Thukkani, and D. A. Ford. 2001. Reactive chlorinating species prodnced by myeloperoxidase target the vinyl ether bond of plasmalo-gens Identification of 2-chlorohexadecanal. J Biol Chem 276(26) 23733-41. 

Thukkani, A. K., C. J. Albert, K. R. Wildsmith, M. C. Messner, B. D. Martinson, F. F. Hsu, and D. A. Ford. 2003a. Myeloperoxidase-derived reactive chlorinating species from human monocytes target plasmalogens in low density lipoprotein. 278(38) 36365-72. 

Reactive Oxygenated Species (ROS) Not only can reactive radicals (arising from oxygen or chlorine evolution) be... 

However, with the more reactive chlorine, chlorination can occur at either position, though the major product is the benzylic halide. Benzylic bromina-tion is also efficiently achieved by the use of N-bromosuccinimide as the halogenating species. 

Note that the free chlorine atom is also a free radical, a very reactive chemical species that may react with other atoms, molecules, and free radicals with which it has contact. For example, free chlorine reacts with ozone molecules to produce diatomic oxygen and the chlorosyl radical (CIO ) ... 

Other species that can initiate this sulfur oxidation chemistry are N03 (discussed in Chapter 7.D.1) and ClJ. The latter radical anion is formed in sea salt particles when atomic chlorine is generated and reacts with chloride ion. In addition, Vogt et al. (1996) have proposed that oxidation of SO2- by HOC1 and HOBr in sea salt particles may be quite important. Table 8.13 summarizes the aqueous-phase chlorine chemistry that occurs in sea salt particles and Table 8.14 the oxidation of S(IV) by reactive chlorine and bromine species in solution. 

CFCs) and halons over the next decade, as mandated by the Montreal Protocol for the Protection of the Ozone Layer, will affect the chlorine burden of the stratosphere. Hydrochlorofluorocarbons (HCFCs) can be used as substitutes for the CFCs for a few decades without having a substantial impact on the chlorine burden of the stratosphere because they are primarily destroyed in the troposphere by reactions with OH before they are able to deliver the chlorine to the stratosphere. The elimination of CFCs and the temporary use of HCFCs into the early part of the next century must be carefully orchestrated to minimize the peak chlorine loading and promote the most rapid reduction of the chlorine burden of the stratosphere (56, 87). Another issue is the effects that perturbations to the reactive nitrogen abundances will have on the abundances of reactive chlorine. A better understanding and clarification of the direct heterogeneous conversions of chlorine species on both PSCs and sulfate aerosols are also needed. 

The effectiveness of various chlorine oxidants, and the influence of the pH, on D-galacturonic acid has been studied (see Ref. 1, p. 1120). The autocatalytic chlorite oxidation of polysaccharides is similar to that described for the bromate oxidation (see Section II.2). Thus, the reactive oxyhalogen species are reduced to halides, as shown in Eq. (26). 

The amount of grafted metal is usually low, for several possible reasons low support OH reactivity, chlorination of the surface, and release of metal species during hydrolysis. Bond and Bruckman [30] mentioned that it is difficult to obtain a monolayer of vanadium species on Ti02 because of the chlorination of the support surface by the HC1 evolved during the anchoring of VOCI3 at 313 K. 

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