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Atmospheric chemistry of 1,3,5-trioxane: UV spectra of c-C3H5O3(•) and (c-C3H5O3)O2(•) radicals, kinetics of the reactions of (c-C3H5O3)O2(•) radicals with NO and NO2, and atmospheric fate of the alkoxy radical

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningfagfællebedømt

  • J. Platz
  • L. K. Christensen
  • J. Sehested
  • Nielsen, Ole John
  • T. J. Wallington
  • C. Sauer
  • Ian Barnes
  • K. H. Becker
  • R. Vogt

A pulse radiolysis technique was used to measure the UV absorption spectra of c-C3H5O3(•) and (c-C3H5O3)-O2(•) radicals over the range 220-300 nm, with σ(c-C3H5O3(«))250 nm = (5.2 ± 0.7) × 10-18 and σ((c-C3H5O3)-O2(•)) 250 nm = (3.7 ± 0.4) × 10-18 cm2 molecule-1. The self-reaction rate constant for the c-C3H5O3(•) radicals, defined as d[c-C3H5O3(•)]/dt = 2k4[c-C3H5O3(•)]2, was k4 = (3.1 ± 0.6) × 10-11 cm3 molecule-1 s-1. The rate constants for reactions of (c-C3H5O3)O2(•) radicals with NO and NO2 were k6 = (5.8 ± 1.4) × 10-12 and k7 = (1.1 ± 0.2) × 10-11 cm3 molecule-1 s-1, respectively. The rate constants for the reaction of F atoms with 1,3,5-trioxane and the reaction of c-C3H5O3(•) radicals with O2 were k3 = (1.1 ± 0.4) × 10-10 and k2 = (7.4 ± 1.1) × 10-12 cm3 molecule-1 s-1, respectively. Relative rate techniques were used to measure the rate constants for the reactions of OH radicals and Cl atoms with 1,3,5-trioxane and Cl atoms with H(O)-COCH2OC(O)H, k20 = (6.0 ± 1.0) × 10-12, k24 = (1.0 ± 0.2) × 10-10, and k25 = (5.1 ± 1.0) × 10-13 cm3 molecule-1 s-1, respectively. FTIR-smog chamber systems were used to show that the atmospheric fate of the alkoxy radical (c-C3H5O3)O(•) is decomposition via C-O bond scission leading to the formation of H(O)-COCH2OC(O)H (methylene glycol diformate). The IR spectrum of the peroxynitrate (c-C3H5O3)O2NO2 is presented. The results are discussed with respect to the atmospheric chemistry of 1,3,5-trioxane.

OriginalsprogEngelsk
TidsskriftJournal of Physical Chemistry A
Vol/bind102
Udgave nummer25
Sider (fra-til)4829-4838
Antal sider10
ISSN1089-5639
StatusUdgivet - 18 jun. 1998

ID: 225754912