Publication
Title
Impact of ligand protonation on eigen-type metal complexation kinetics in aqueous systems
Author
Abstract
The impact of ligand protonation on metal speciation dynamics is quantitatively described. Starting from the usual situation for metal complex formation reactions in aqueous systems, i.e., exchange of water for the ligand in the inner coordination sphere as the rate-determining step (Eigen mechanism), expressions are derived for the lability of metal complexes with protonated and unprotonated ligand species being involved in formation of the precursor outer-sphere complex. A differentiated approach is developed whereby the contributions from all outer-sphere complexes are included in the rate of complex formation, to an extent weighted by their respective stabilities. The stability of the ion pair type outer-sphere complex is given particular attention, especially for the case of multidentate ligands containing several charged sites. It turns out that in such cases, the effective ligand charge can be considerably different from the formal charge. The lability of Cd(II) complexes with 1,2-diaminoethane-N,N'-diethanoic acid at a microelectrode is reasonably well predicted by the new approach.
Language
English
Source (journal)
The journal of physical chemistry : A : molecules, spectroscopy, kinetics, environment and general theory. - Washington, D.C., 1997, currens
Publication
Washington, D.C. : 2007
ISSN
1089-5639 [print]
1520-5215 [online]
DOI
10.1021/JP0673009
Volume/pages
111 :11 (2007) , p. 2115-2121
ISI
000244896100012
Full text (Publisher's DOI)
UAntwerpen
Publication type
Subject
External links
Web of Science
Record
Identifier
Creation 12.01.2017
Last edited 22.02.2023
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