Direct evidence for base-mediated decomposition of alkyl hydroperoxides (ROOH) in the gas phase.
The reaction of F(-) with CH(3)OOH has been studied in the gas phase using a tandem flowing afterglow-selected ion flow tube apparatus. The reaction is rapid (k = 1.23 x 10(-9) cm(3) s(-1), 49% efficiency), and formation of HO(-) + CH(2)O + HF is the major reaction channel observed (85%). Isotopic labeling, reactions of F(-) with larger alkyl hydroperoxides, and computational studies demonstrate that the major product ion, HO(-), is formed via a concerted elimination mechanism that appears to be general to all alkyl hydroperoxides possessing an alpha-hydrogen. This mechanism represents a base-mediated decomposition of alkyl hydroperoxides in the gas phase that may have important implications for solution and biochemical reactions. The reverse reaction, CH(3)OO(-) + HF is also efficient (k = 2.43 x 10(-9) cm(3) s(-1)). The major product ensemble HO(-) + CH(2)O + HF (81%) is identical to that of the forward reaction, and represents a novel neutral-catalyzed decomposition of the anion.
Blanksby
Stephen J
SJ
Department of Chemistry and Biochemistry, University of Colorado, Boulder, CO 80309, USA.
Ellison
G Barney
GB
Bierbaum
Veronica M
VM
Kato
Shuji
S
D005740:Gases; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D015227:Lipid Peroxidation; D010545:Peroxides / Q000737:chemistry*; D013816:Thermodynamics
D005740:Gases; D010545:Peroxides