Pcroxynitrlc ac~d has been idcntlficd by I~our~cr transform, infrared, long-path spectroscopy as a product of the UVirrndratcd ddutc mi\turcs of llON0, CO, NO, in synthctrc air at 24 L 2Β°C'. The characteristic pcnks of this compound arc idcntrcnl to those obscrvcd by Nikl ct al., in Irr.ulratcd Clz, 112, NOz, arr mixtures and flan%t ct al., in irr.ldiatcd C 12. CZlzO, NO*, nlr nuxturcc. The conentrdtlons of the rcxt.mtF dnd products of the HONO,CO, NO,, arr system have hcen dctcrmmcd 3~ 3 function of irradiation time The changes observed were computer simulated using 3 combimltion of thirty elementary renctrons. 171~ datd ~ggcst that both reactions (I) and (2) occur as rl result of H02--NOz interactions in thegas phac: HO2 + NO2 --+ HONO + O2 (1); 1102 + NO1 (+hl) +I 102 NO2 (+&I) (2). The data give the preliminary cstimates:kt /kz CO.7 f 0.4; kl /kx = 0.043 f 0.02; kz/k3 = 0.058 + 0.02, whcrc reaction (3) is-II02 + NO-IIO+ NO2.Thcse dd1a and computer Gmulatrons of sunhyht-~rmdiated, NO,, hydrocarbon, ,Wztlydc-polluted
atmosphcrcs suggest that pcroxymtric acid may bc formed in urh.m atrnoqphcrcs at rates which rlrc comparable to those obscrvcd for pcrovyaretyl nitrate (PAN), and it is conciuded that II02N02 may contrlbutc to the "oxid.mt" found in these atmospheres.