Kinetic study of the reduction of neptunium (VII) and americium (VI) by bromide ion in aqueous perchlorate media
The oxidation of Br- to bromine by the actinides, Am(VI) and Np(VII), has been found to proceed by the rate laws -/sup 1///sub 2/(d ln (Am(VI))/dt) = k/sub 1/(Br/sup -/) + k/sub 2/(Br/sup -/)/sup 2/ and -d ln (Np(VII))/dt = (Br/sup -/)(k/sub 1/(H/sup +/) + k/sub 2/(H/sup +/)/sup 2/). The apparent activation parameters are ..delta..H/sub 1//sup + +/ = 15.7 +- 0.1 kcal/mol, ..delta..H/sub 2//sup + +/ = 12.5 +- 0.1 kcal/mol, ..delta..S/sub 1//sup + +/ = 2.5 +- 2.7 eu, and ..delta..S/sub 2//sup + +/ = -1.5 +- 1.6 eu for Am(VI) and ..delta..H/sub 1//sup + +/ = 9.4 +- 0.3 kcal/mol, ..delta..H/sub 2//sup + +/ = 3.9 +- 0.5 kcal/mol, ..delta..S/sub 1//sup + +/ = -8.8 +- 1.1 eu, and ..delta..S/sub 2//sup + +/ = -26.3 +- 1.8 eu for Np(VII). The rate laws are accounted for by mechanisms consistent with other oxidations of Br/sup -/ and are compared with similar rate laws observed for the dioxo cation, VO/sub 2//sup +/.
- Research Organization:
- Argonne National Lab., IL
- OSTI ID:
- 7210488
- Journal Information:
- Inorg. Chem.; (United States), Journal Name: Inorg. Chem.; (United States) Vol. 16:9; ISSN INOCA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
400702* -- Radiochemistry & Nuclear Chemistry-- Properties of Radioactive Materials
ACTINIDE COMPOUNDS
AMERICIUM COMPOUNDS
BROMIDES
BROMINE COMPOUNDS
CHEMICAL REACTIONS
HALIDES
HALOGEN COMPOUNDS
HYDROGEN COMPOUNDS
INORGANIC ACIDS
KINETICS
NEPTUNIUM COMPOUNDS
OXIDATION
PERCHLORIC ACID
REACTION KINETICS
REDUCTION
THERMODYNAMICS
TRANSURANIUM COMPOUNDS