Chelating Polymers. IV. Monomeric N-Hydroxyalkylaminoacetic Acids as Chelating Compounds

Abstract

Abstract The compounds N-(2-hydroxy-2-phenylethyl)aminoacetic acid and N-(2-hydroxy-2-phenylethyl)iminodiacetic acid were prepared and then characterized by elemental analysis, thermogravimetric analysis, ir spectroscopy, solubility studies, and potentiometric titration studies. They were reacted with PrCl3, HoCl3, YbCl3and Cu(NO3)2. The resulting rare earth complexes were analyzed by elemental analysis, ir spectroscopy, thermogravimetric analysis, and stability constant determinations. The stability constants of the aminoacetic acid and the iminodiacetic acid complexes of these same rare earths were also determined. All of the stability constants were measured using a potentiometric titration technique in 50% v/v dioxane-water at 25°C and at an ionic strength of 0.1 (KC1). The copper complexes were analyzed by ir spectroscopy and thermogravimetric analysis, and their properties were compared to those of the rare earth complexes. The results suggest chelation in all of the metal complexes. They further suggest that the alcoholic oxygen atom in both of the prototype ligands acts as a donor in the rare earth chelates but not in the copper complex.