Solution equilibria between ethylenediamine-N,N'-di-3-propionate and some transition metal(II) ions.

ABSTRACT

Solution equilibria between the ligand ethylenediamine-N,N'-di-3-propionate (eddp(2-)) and copper(II), nickel(II) or cobalt(II) ions were studied by glass electrode pH-metric and spectrophotometric measurements in 0.1 M NaCl ionic medium at 298.0+/-0.2 K. In the concentration limits 1.0metal(II)]treatment Cu(eddp), 14.23+/-0.04; Cu(Heddp), 16.17+/-0.08; Cu(OH)eddp, 3.08+/-0.06; Ni(eddp), 8.89+/-0.02; Ni(OH)eddp, -2.15+/-0.06; Co(eddp), 7.16+/-0.03; Co(OH)eddp, -0.83+/-0.04; Co(OH)(2)eddp, -10.54+/-0.05. The mechanism of the formation and structure of the complexes, as well as their possible analytical use, were discussed.