Enhanced formation of ozone by the addition of chloropicrin (trichloronitromethane) to propene/NO/air/photoirradiation systems

Article abstract of DOI:10.1246/bcsj.72.1497

The photolysis of chloropicrin in air at 1 atm was performed in a 6-m³ photochemical reaction chamber with a combination of Xe arc lamps and Pyrex filters as a light source. Phosgene was obtained as one of the main products with a yield of unity. No nitrosyl chloride was observed, which supports the C-N scission mechanism for the photolysis. Photochemical ozone formation was enhanced when chloropicrin was added to the propene/NO/air/photoirradiation system after the ozone concentration maximum had been reached. The ozone- formation factor for chloropicrin under the conditions employed was, however, estimated to be 0.25 mole of ozone formed per mole of the decomposed chloropicrin. This implies that the Cl atom, itself, contributes to the destruction of ozone rather than to the formation of Ozone under the experimental conditions. NO₂ released from chloropicrin is the source of enhanced ozone. If the amount of chloropicrin as a soil fumigant increases, it can cause an increase of the ozone concentration in suburban and/for rural areas.