PROTON NUCLEAR MAGNETIC RESONANCE STUDIES OF SOME ETHYLENEDIAMINETETRAACETIC ACID AND ETHYLENEDIAMINEDIACETIC ACID COMPLEXES OF PALLADIUM(2)

Several complexes of ethylenediaminetetraacetic acid (EDTA) and ethylenediaminediacetic acid (EDDA) with palladium(II) have been prepared and proton nmr spectra of their aqueous (D2O) solutions have been studied as a function of pH and temperature. In most cases the spectra exhibit AB splitting patterns for the ligand acetate protons. For the Pd(H4EDTA)Cl2 and Pd(H2EDDA)Cl2 complexes1 the spectra indicate that a mixture of bidentate and tridentate species is present in solution. The spectra of the tetradentate Pd(H2EDTA) complex exhibit AB patterns for the two different types of acetate protons (free and uncomplexed). The tetradentate Pd(EDDA) complex is not sufficiently soluble in D2O to permit nmr studies. The infrared spectra of the complexes in both solution and solid phases also have been measured; they indicate that the bidentate complexes contain some tridentate species. © 1969, American Chemical Society. All rights reserved.