TY - JOUR
T1 - Kinetic and thermodynamic parameters of copper-dioxygen interaction with different oxygen binding modes
AU - Karlin, Kenneth D.
AU - Tolman, William B.
AU - Kaderli, Susan
AU - Zuberbühler, Andreas D.
PY - 1997/3/14
Y1 - 1997/3/14
N2 - Kinetic and thermodynamic parameters for metal ion-O2 interaction have been obtained for a variety of copper(I) complexes with different binding modes for dioxygen. In general, favorable binding enthalpies of up to 80 kJ mol-1 are compensated by strongly negative reaction entropies up to -220 J K-1 mol-1 restricting the range of overall stabilities. Sequential formation of superoxo and peroxo complexes, as well as concomitant formation of η1:η1 and η2:η2 μ-peroxo complexes has been established by low-temperature stopped-flow experiments. In several cases, pseudoreversible binding of dioxygen is followed by an irreversible oxidation of the organic ligand. A recent result is the identification of a rapid equilibrium between an η2:η2 μ-peroxo complex and the isomeric bis-μ oxo compound with broken O-O bond which may be fundamental to several O2 dependent redox enzymes.
AB - Kinetic and thermodynamic parameters for metal ion-O2 interaction have been obtained for a variety of copper(I) complexes with different binding modes for dioxygen. In general, favorable binding enthalpies of up to 80 kJ mol-1 are compensated by strongly negative reaction entropies up to -220 J K-1 mol-1 restricting the range of overall stabilities. Sequential formation of superoxo and peroxo complexes, as well as concomitant formation of η1:η1 and η2:η2 μ-peroxo complexes has been established by low-temperature stopped-flow experiments. In several cases, pseudoreversible binding of dioxygen is followed by an irreversible oxidation of the organic ligand. A recent result is the identification of a rapid equilibrium between an η2:η2 μ-peroxo complex and the isomeric bis-μ oxo compound with broken O-O bond which may be fundamental to several O2 dependent redox enzymes.
KW - Activation parameters
KW - Copper complexes
KW - Copper protein models
KW - Dioxygen binding
KW - Dioxygen carriers
KW - Stoppped-flow kinetics
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U2 - 10.1016/S1381-1169(96)00250-6
DO - 10.1016/S1381-1169(96)00250-6
M3 - Article
AN - SCOPUS:0030901787
VL - 117
SP - 215
EP - 222
JO - Journal of Molecular Catalysis A: Chemical
JF - Journal of Molecular Catalysis A: Chemical
SN - 1381-1169
IS - 1-3
ER -