These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Kinetics of the gas-phase reactions of OH and NO3 radicals and O3 with 1,4-thioxane and 1,4-dithiane.
    Author: Aschmann SM, Long WD, Atkinson R.
    Journal: J Phys Chem A; 2008 Dec 25; 112(51):13556-65. PubMed ID: 19093823.
    Abstract:
    Rate constants for the gas-phase reactions of the cyclic organosulfur compounds 1,4-thioxane and 1,4-dithiane with NO(3) radicals and O(3) have been measured at 296 +/- 2 K, and rate constants for their reactions with OH radicals have been measured over the temperature range 278-350 K. Relative rate methods were used to measure rate constants for the OH radical and NO(3) radical reactions. The OH radical reaction in the presence of NO(x) and, to a lesser extent, the NO(3) radical reaction were subject to secondary reactions leading to additional removal of 1,4-thioxane and/or 1,4-dithiane. The rate constants obtained for the NO(3) radical and O(3) reactions at 296 +/- 2 K were (5.1 +/- 1.1) x 10(-14) cm(3) molecule(-1) s(-1) and <2 x 10(-19) cm(3) molecule(-1) s(-1), respectively, for 1,4-thioxane and (5.9 +/- 1.8) x 10(-14) cm(3) molecule(-1) s(-1) and <2.5 x 10(-19) cm(3) molecule(-1) s(-1), respectively, for 1,4-dithiane. For the OH radical reactions, the temperature-dependent rate expressions obtained were k(OH + 1,4-thioxane) = 2.54 x 10(-12) e((619+/-51)/T) cm(3) molecule(-1) s(-1) (278-349 K) and k(OH + 1,4-dithiane) = 3.71 x 10(-12) e((621+/-163)/T) cm(3) molecule(-1) s(-1) (278-350 K), with 298 K rate constants of (2.03 +/- 0.41) x 10(-11) cm(3) molecule(-1) s(-1) for 1,4-thioxane and (2.98 +/- 0.75) x 10(-11) cm(3) molecule(-1) s(-1) for 1,4-dithiane. For the experimental conditions employed, aerosol formation from the OH radical-initiated reactions of both 1,4-thioxane and 1,4-dithiane was important, accounting for approximately 60% of the organosulfur compounds reacted in both the presence and absence of NO(x). The data obtained here for 1,4-thioxane and 1,4-dithiane are compared with literature data for the corresponding reactions of simple acyclic alkyl sulfides and ethers.
    [Abstract] [Full Text] [Related] [New Search]