Leoš Bláha, Ivan Lukeš, Jan Rohovec and Petr Hermann
The complexing properties of aminomethylphosphonic acid, Gly-(P), and glycylaminomethylphosphonic acid, Gly-Gly-(P), with PtII and PdII were investigated pH-metrically at 25 °C and at an ionic strength of 0.1 mol dm-3 (KNO3) using ‘out of cell’ titrations. The stability constants calculated indicate formation of complexes with a metal∶ligand molar ratio of 1∶1 and 1∶2. The species and their distribution determined pH-metrically were confirmed by 31P and 1H NMR titrations. Comparison of our results for Gly-(P) and Gly-Gly-(P) with those for glycine and glycylglycine and other common dipeptides shows that the complexing properties of PdII and PtII towards both types are very similar.