Further studies on the kinetics and mechanism of the copper-imidazole catalyzed decomposition of hydrogen peroxide

Journal Article · Thu Dec 01 04:00:00 EST 1988 · J. Coord. Chem.; (United States)

DOI:https://doi.org/10.1080/00958978808080975· OSTI ID:6048400

Ferreira, A M.C.; Toma, H E

The catalytic decomposition of hydrogen peroxide in the presence of the tetrakis(imidazole)copper(II) complex was investigated. The kinetics, based on the rates of oxygen evolution, indicated that a ternary copper(II)-imidazole-peroxo complex is involved in the rate-determining step. The equilibrium constant for the coordination of hydrogen peroxide to the cupric ion, and the acid dissociation constant for the coordinated H/sub 2/O/sub 2/ ligand were calculated as 1.7 M/sup /minus/1/ and 2.1 /times/ 10/sup /minus/9/ M, respectively. The ternary complex undergoes intramolecular electron transfer, with k = 4 s/sup /minus/1/, generating Cu(I) species which can react with hydrogen peroxide or dioxygen, returning to the catalytic cycle. A complete mechanism is proposed, based on the kinetics of oxygen and on the electrocatalytic behavior observed for the copper-imidazole complexes under a dioxygen atmosphere.

• Research Organization: Universidade de Sao Paulo (Brazil)
• OSTI ID: 6048400
• Journal Information: J. Coord. Chem.; (United States), Journal Name: J. Coord. Chem.; (United States) Vol. 18:4; ISSN JCCMB
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
AZOLES
CATALYSIS
CATALYSTS
CATALYTIC EFFECTS
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
COMPLEXES
COPPER COMPLEXES
DATA
DECOMPOSITION
EXPERIMENTAL DATA
HETEROCYCLIC COMPOUNDS
HYDROGEN COMPOUNDS
HYDROGEN PEROXIDE
IMIDAZOLES
INFORMATION
KINETICS
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXYGEN COMPOUNDS
PEROXIDES
REACTION KINETICS
TRANSITION ELEMENT COMPLEXES