Geminate recombination of hydroxyl radicals generated in 200 nm photodissociation of aqueous hydrogen peroxide.

Journal Article · Thu Jan 15 04:00:00 EST 2004 · Chem. Phys. Lett.

DOI:https://doi.org/10.1016/j.cplett.2003.11.062· OSTI ID:961477

Crowell, R A; Lian, R; Oulianov, D A; Shkrob, I A

The picosecond dynamics of hydroxyl radicals generated in 200 nm photoinduced dissociation of aqueous hydrogen peroxide have been observed through their transient absorbance at 266 nm. It is shown that these kinetics are nearly exponential, with a decay time of ca. 30 ps. The prompt quantum yield for the decomposition of H2O2 is 0.56, and the fraction of hydroxyl radicals escaping from the solvent cage to the water bulk is 64-68%. These recombination kinetics suggest strong caging of the geminate hydroxyl radicals by water. Phenomenologically, these kinetics may be rationalized in terms of the diffusion of hydroxide radicals out of a shallow potential well (a solvent cage) with an Onsager radius of 0.24 nm.

• Research Organization: Argonne National Laboratory (ANL)
• Sponsoring Organization: SC
• DOE Contract Number: AC02-06CH11357
• OSTI ID: 961477
• Report Number(s): ANL/CHM/JA-48229
• Journal Information: Chem. Phys. Lett., Journal Name: Chem. Phys. Lett. Journal Issue: 5-6 ; Jan. 15, 2004 Vol. 383; ISSN CHPLBC; ISSN 0009-2614
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
DECAY
DECOMPOSITION
DIFFUSION
DISSOCIATION
DYNAMICS
HYDROGEN PEROXIDE
HYDROXIDES
HYDROXYL RADICALS
KINETICS
RADICALS
RECOMBINATION
SOLVENTS
TRANSIENTS
WATER