Hydrogen atom transfer in the oxidation of hydrogen peroxide by ((bpy)/sub 2/(py)Ru/sup IV/ double bond O)/sup 2 +/ and by ((bpy)/sub 2/(py)Ru/sup III/ single bond OH)/sup 2 +/

Journal Article · Wed Apr 08 04:00:00 EDT 1987 · Inorg. Chem.; (United States)

DOI:https://doi.org/10.1021/ic00254a031· OSTI ID:6488517

Gilbert, J; Roecker, L; Meyer, T J

The oxidations of H/sub 2/O/sub 2/ and of HO/sub 2//sup -/ by ((bpy)/sub 2/(py)Ru/sup III/(OH))/sup 2 +/ have been studied in aqueous solution. Rate constants and activation parameters for the oxidation of H/sub 2/O/sub 2/ by Ru/sup IV/ double bond O/sup 2 +/ are k(25/sup 0/C) = 1.74 +/- 0.18, ..delta..H/sup double dagger/ = 6.0 +/- 0.3 kcal/mol, and ..delta..S/sup double dagger/ = -37 +/- 3 eu and by Ru/sup III/-OH/sup 2 +/ are k(25/sup 0/C) = (8.09 +/- 0.27) x 10/sup -2/, ..delta..H/sup double dagger/ = 12 +/- 2 kcal/mol, and ..delta..S/sup double dagger = -38 +/- 3 eu. H/sub 2/O/D/sup 2/O kinetic isotope ratios are, for Ru/sup IV /double bond O/sup 2 +/, (k/sub H/sub 2/O/ /sup 250/C/k/sub D/sub 2/O /sup 250/C) = 22.0 +/- 1.2 and, for Ru/sup III/double bond OH/sup 2 +/, (k/sub H/sub 2/O /sup 250/C)/k/sub D/sup 2/O/ /sup 250/C) = 16.2 +/- 0.7. From rapid-mixing experiments ((bpy)/sub 2/(py)Ru/sup III/(OH))/sup +/ is the initial product of the oxidation of H/sub 2/O/sub 2/ by Ru/sup IV/ double bond O/sup 2 +/ rather than ((bpy)/sub 2/(py)Ru/sup II/(OH/sub 2/))/sup 2 +/, and it is proposed that oxidation of H/sub 2/O/sub 2/ by both Ru/sup IV/double bond O/sup 2 +/ and Ru/sup III/ single bond OH/sup 2 +/ occurs by H atom (1e-1 H/sup +/) transfer. 38 references, 5 figures, 4 tables.

• Research Organization: Univ. of North Carolina, Chapel Hill
• OSTI ID: 6488517
• Journal Information: Inorg. Chem.; (United States), Journal Name: Inorg. Chem.; (United States) Vol. 26:7; ISSN INOCA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400202* -- Isotope Effects
Isotope Exchange
& Isotope Separation
AZINES
BIPYRIDINES
CHEMICAL REACTIONS
HEAVY WATER
HETEROCYCLIC COMPOUNDS
HYDROGEN COMPOUNDS
HYDROGEN PEROXIDE
ISOTOPE RATIO
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXIDATION
OXYGEN COMPOUNDS
PEROXIDES
PYRIDINES
REDOX REACTIONS
REFRACTORY METAL COMPOUNDS
RUTHENIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
WATER