title: 2,3-Dimethyl-2-butene (TME) ozonolysis: pressure dependence of stabilized Criegee intermediates and evidence of stabilized vinyl hydroperoxides.
abstract: We present measurements of the pressure dependence of stabilized Criegee intermediate (SCI) formation utilizing a hexafluoroacetone scavenger. SCI yields in the ozonolysis of 2,3-dimethyl-2-butene (TME) were measured in a high pressure flow reactor within a range of 50-710 Torr. Within this pressure range, SCI yields increase linearly with pressure. A zero pressure intercept of about 15% indicates that a significant fraction of CI are formed below the barrier to isomerization. By comparison of our results of the pressure dependence of SCI formation and both prompt and long-time OH yields, our results indicate that OH formation from ozonolysis proceeds via at least two intermediates, the SCI and presumably a vinylhydroperoxide (VHP).
authors.affiliation: Carnegie Mellon, University, Pittsburgh, Pennsylvania, USA. gdrozd@andrew.cmu.edu
authors.forename: Greg T
authors.initials: GT
authors.lastname: Drozd
authors.forename: Jesse
authors.initials: J
authors.lastname: Kroll
authors.forename: Neil M
authors.initials: NM
authors.lastname: Donahue
mesh_terms: D000096:Acetone / Q000031:analogs & derivatives / Q000737:chemistry; D000475:Alkenes / Q000737:chemistry*; D005466:Fluorocarbons / Q000737:chemistry; D016166:Free Radical Scavengers / Q000737:chemistry; D054879:Halogenation; D006571:Heterocyclic Compounds / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000737:chemistry*; D010126:Ozone / Q000737:chemistry*; D011312:Pressure; D006845:Hydrocarbons, Fluorinated
chemical_list: D000096:Acetone; D000475:Alkenes; D005466:Fluorocarbons; D016166:Free Radical Scavengers; D006571:Heterocyclic Compounds; D006861:Hydrogen Peroxide; D010126:Ozone; C503429:1,2,4-trioxane; C040216:2,3-dimethyl-2-butene; C017366:hexafluoroacetone; D006845:Hydrocarbons, Fluorinated