Linear Free Energy Relationships for Metal-Ligand Complexation: Bidentate Binding to Negatively-Charged Oxygen Donor Atoms.

ABSTRACT: Stability constants for metal complexation to bidentate ligands containing negatively-charged oxygen donor atoms can be estimated from the following linear free energy relationship (LFER): log K(ML) = χ(OO)(α(O) log K(HL,1) + α(O) log K(HL,2)) where K(ML) is the metal-ligand stability constant for a 1:1 complex, K(HL,1) and K(HL,2) are the proton-ligand stability constants (the ligand pK(a) values), and α(O) is the Irving-Rossotti slope. The parameter χ(OO) is metal specific and has slightly different values for 5 and 6 membered chelate rings. LFERs are presented for 21 different metal ions and are accurate to within approximately 0.30 log units in predictions of log K(ML) values. Ligands selected for use in LFER development include dicarboxylic acids, carboxyphenols, and ortho-diphenols.

SUBMITTER: Carbonaro RF 

PROVIDER: S-EPMC3151533 | biostudies-literature | 2011 May

REPOSITORIES: biostudies-literature