Formyl radical tropospheric, reaction

Peroxy radicals are also formed in the troposphere through the photolysis of aldehydes (10, 11) and through nitrate radical (N03) reactions (12-14). The hydrogen atom and formyl radical that are formed then react with molecular oxygen (02) (reactions 11 and 12) under tropospheric conditions. 

Photolytic. Irradiation of vinyl chloride in the presence of nitrogen dioxide for 160 min produced formic acid, HCl, carbon monoxide, formaldehyde, ozone, and trace amounts of formyl chloride and nitric acid. In the presence of ozone, however, vinyl chloride photooxidized to carbon monoxide, formaldehyde, formic acid, and small amounts of HCl (Gay et al, 1976). Reported photooxidation products in the troposphere include hydrogen chloride and/or formyl chloride (U.S. EPA, 1985). In the presence of moisture, formyl chloride will decompose to carbon monoxide and HCl (Morrison and Boyd, 1971). Vinyl chloride reacts rapidly with OH radicals in the atmosphere. Based on a reaction rate of 6.6 x lO" cmVmolecule-sec, the estimated half-life for this reaction at 299 K is 1.5 d (Perry et al., 1977). Vinyl chloride reacts also with ozone and NO3 in the gas-phase. Sanhueza et al. (1976) reported a rate constant of 6.5 x 10 cmVmolecule-sec for the reaction with OH radicals in air at 295 K. Atkinson et al. (1988) reported a rate constant of 4.45 X 10cmVmolecule-sec for the reaction with NO3 radicals in air at 298 K. 

PROBABLE FATE photolysis, no information available pertaining to the rate of photodissociation in aqueous environment, photodissociation to formyl chloride may occur in stratosphere, predominate fate process, if released to the atmosphere, is the reaction with photochemi-cally produced hydroxyl radicals with an estimated half-life of 40 days, less than 1% will eventually diffuse above the ozone layer where it will be destroyed by photolysis, direct photolysis is not important oxidation photooxidation in troposphere is the primary fate mechanism, photo-... 

Chemical oxidation is not significant in the fate of chloromethanes in natural waters, but once volatilized and present in the troposphere, chloromethanes are attacked by hydroxyl radicals via hydrogen abstraction. The rates of reaction and the half-life for chloromethanes are given in Table 3.6. The principal products of this photooxidation reaction are reported to be formyl... 

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