LIF studies of iodine oxide chemistry. Part 3. Reactions IO + NO3 --> OIO + NO2, I + NO3 --> IO + NO2, and CH2I + O2 --> (products): implications for the chemistry of the marine atmosphere at night.
The technique of pulsed laser photolysis coupled to LIF detection of IO was used to study IO + NO(3) --> OIO + NO(2); I + NO(3) --> (products); CH(2)I + O(2) --> (products); and O((3)P) + CH(2)I(2) --> IO + CH(2)I, at ambient temperature. was observed for the first time in the laboratory and a rate coefficient of k(1 a) = (9 +/- 4) x 10(-12) cm(3) molecule(-1) s(-1) obtained. For , a value of k(2) (298 K) = (1.0 +/- 0.3) x 10(-10) cm(3) molecule(-1) s(-1) was obtained, and a IO product yield close to unity determined. IO was also formed in a close-to-unity yield in , whereas in an upper limit of alpha(3)(IO) < 0.12 was derived. The implications of these results for the nighttime chemistry of the atmosphere were discussed. Box model calculations showed that efficient OIO formation in was necessary to explain field observations of large OIO/IO ratios.
Dillon
Terry J
TJ
Max-Planck-Institut für Chemie, Division of Atmospheric Chemistry, Postfach 3060, 55020 Mainz, Germany. dillon@mpch-mainz.mpg.de
Tucceri
María E
ME
Sander
Rolf
R
Crowley
John N
JN
D000465:Algorithms; D001272:Atmosphere / Q000737:chemistry*; D003624:Darkness; D006847:Hydrocarbons, Iodinated / Q000737:chemistry*; D017613:Iodine Compounds / Q000737:chemistry*; D007700:Kinetics; D008956:Models, Chemical; D009569:Nitric Oxide / Q000737:chemistry*; D009585:Nitrogen Dioxide / Q000737:chemistry*; D009792:Oceans and Seas; D010100:Oxygen / Q000737:chemistry*; D010782:Photolysis
D006847:Hydrocarbons, Iodinated; D017613:Iodine Compounds; D009569:Nitric Oxide; D009585:Nitrogen Dioxide; D010100:Oxygen