Halogenated organic compounds atmosphere

Tetracarbonylnickel(O), a very toxic chemical, is rather reactive. It is oxidized by atmospheric O2 in the gas phase and it reacts with halogenated organic compounds to form e corresponding Ni(II) halides . ... 

Methyl iodide is also present in the atmosphere in highly variable amounts, averaging about one part in 10 much higher concentrations are present in seawater (Lovelock et al., 1973). It is likely that other halogenated organic compounds of natural origin are also present in the atmosphere for example, a host of C1-, Br- and... 

Clearly reactions (2), (3), (4) and (5) could all play significant roles in the atmospheric degradation of halogenated organic compounds. Kinetic data for reactions (3), (4) and (5) are needed for a more complete understanding of the atmospheric chemistry for halogenated organic compounds. 

The presence of ionizing radiation in the upper regions of the earth s atmosphere and the realization that atmospheric chemistry can occur on the surface of ice and dust particles have lead many authors to study on the interaction of LEE with molecular solids of ozone [203], HCl [236], and halogen-containing organic compounds [176,177,195-197,199-202,205,214,217,224-234] in an effort to shed new light on the problem of ozone depletion. In a recent series of experiments, Lu and Madey [297,298] found that the and CG yields... 

Studies of the reactions of many atmospherically important atomic and free radical species were described in Section 9 this Section deals primarily with important molecular species. A brief review of the progress achieved recently in the field of atmospheric chemistry has been provided by Cox, " with emphasis on the reactions of O3 and important H-, N-, C-, halogen-, and S-containing species. Waynehas reviewed extraterrestrial atmospheric photochemistry and Strobel " has reviewed the photochemistries of the atmospheres of Jupiter, Saturn, and Titan. Kaye and Strobeldescribed a 1-dimensional photochemical model of PHj chemistry in the atmosphere of Saturn. A study of the photochemical reactions of H2O and CO in the Earth s primitive atmosphere has been presented by Bar-Nun and Chang. " They concluded that even if the primitive atmosphere initially contained no H2 and contained carbon only in the form of CO and CO2, photochemical processes would have enriched the environment with a variety of organic compounds. 

According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere, bromotrichloromethane, which has a measured vapor pressure of 39mmHg at 25°C, is expected to exist solely as a vapor in the ambient atmosphere. Based on bromotrichloromethane s structural similarity to bromotrifluoromethane, it is expected to slowly degrade in the atmosphere by reaction with photochemically produced hydroxyl radicals the half-life for bromotrichloromethane s reaction in air is estimated to be greater than 44 years. Photolysis may occur based on bromotrichloromethane s structural similarity to other halogenated methane compounds but not at an environmentally relevant rate. 

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