Abstract
The acid-base equilibria of propane 1,2,3-triamine (PTA) and the formation equilibria of binary and ternary complexes of palladium(II) with PTA as primary ligand and amino acid, peptide, and DNA subunits as secondary ligand have been investigated. Pd(II) is found to form a 1:1 complex with PTA. The ternary complexes are formed in a stepwise mechanism, whereby PTA first binds to Pd(II) and then ligates to the secondary ligand. The hydrolysis of the Pd-PTA complex and the deprotonation of the amide residues in the peptide complexes are discussed in relation to physiological conditions.