Organometallic catalysis in aqueous solution. Oxygen transfer to bromide

Journal Article · Wed Apr 06 00:00:00 EDT 1994 · Journal of the American Chemical Society; (United States)

DOI:https://doi.org/10.1021/ja00086a020· OSTI ID:7019550

Espenson, J H; Pestovsky, O; Huston, P; Staudt, S ^[1]

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1. Ames Lab., IA (United States) Iowa State Univ., Ames, IA (United States)

The reaction between hydrogen peroxide and bromide ions in aqueous acidic solutions, ordinarily very slow, is strongly catalyzed by CH[sub 3]ReO[sub 3], a water-soluble organometallic oxide. The complex catalytic kinetics showed that the rate-controlling process consists of two steps: (1) reversible formation of the independently-known 1:1 and 2:1 adducts of hydrogen peroxide and methylrhenium trioxide (the formulas, including the water that had been shown to be coordinated, are CH[sub 3]Re(O)[sub 2]([eta][sup 2]-O[sub 2])(H[sub 2]O) and CH[sub 3]Re(O)([eta][sup 2]-O[sub 2])[sub 2](H[sub 2]O)) and (2) their reactions with bromide ions that yield HOBr. The rate constants for these steps were evaluated by several steady-state kinetic techniques. The HOBr intermediate reacts with Br to yield Br[sub 2]. When hydrogen peroxide was in excess, the reaction yielded oxygen instead of bromine. This can be accounted for by the reaction of HOBr with H[sub 2]O[sub 2]. The 2:1 peroxide-rhenium adduct, formed only at the higher concentrations of hydrogen peroxide, also reacts with bromide ions, but more slowly. Kinetic modeling by numerical techniques was used to provide verification of the reaction scheme. 19 refs., 8 figs., 1 tab.

• DOE Contract Number: W-7405-ENG-82
• OSTI ID: 7019550
• Journal Information: Journal of the American Chemical Society; (United States), Journal Name: Journal of the American Chemical Society; (United States) Vol. 116:7; ISSN JACSAT; ISSN 0002-7863
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400102 -- Chemical & Spectral Procedures
400201* -- Chemical & Physicochemical Properties
99 GENERAL AND MISCELLANEOUS
990200 -- Mathematics & Computers
ADDUCTS
AQUEOUS SOLUTIONS
BROMINE
BROMINE IONS
CATALYSIS
CHARGED PARTICLES
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
COMPLEXES
DISPERSIONS
ELEMENTS
HALOGENS
HYDROGEN COMPOUNDS
HYDROGEN PEROXIDE
IONS
KINETICS
MATHEMATICAL MODELS
MIXTURES
NONMETALS
ORGANIC COMPOUNDS
ORGANOMETALLIC COMPOUNDS
OXYGEN
OXYGEN COMPOUNDS
PEROXIDES
REACTION KINETICS
RHENIUM COMPLEXES
SOLUTIONS
SPECTROPHOTOMETRY
TRANSITION ELEMENT COMPLEXES