Determination of stability constants for metal-ligand complexes using the voltammetric oxidation wave of the anion/ligand and the DeFord and Hume formalism
Gw. Luther et al., Determination of stability constants for metal-ligand complexes using the voltammetric oxidation wave of the anion/ligand and the DeFord and Hume formalism, TALANTA, 51(1), 2000, pp. 11-20
The voltammetric oxidation peaks for anions and other ligands that react at
the Hg electrode can be used for the determination of stability constants
of metal-ligand complexes using the DeFord and Hume formalism. Metal-ligand
complexes with known stability constants that span the range of log beta =
2.9-5.9 were determined using the oxidation wave of the ligand as metal wa
s varied. For the larger stability constants, it was possible to titrate co
ncentrations of metal to ligand that are smaller than the ligand concentrat
ion and obtain reliable data (beta(j)C(x)(j) approaches 1 in this case) ind
icating that an excess of titrant is not required to obtain reliable beta v
alues. Data reduction with different versions of the Solver tool (included
with Microsoft Excel) is discussed and blind use of these programs without
knowledge of the physical chemistry of the system is discouraged. The use o
f Solver gives beta values that are in agreement with previous work that us
ed (non)linear regression to evaluate each F-n(X) versus [X] function. (C)
2000 Elsevier Science B.V. All rights reserved.