Solution equilibria between ethylenediamine-N,N'-di-3-propionate and some transition metal(II) ions.
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 1.0</=[metal(II)]</=5.0, 1.0</=[eddp]</=10.0 and 2.5</=-log[H(+)]</=10.0 mM, the formation of the following complexes with their overall stability constants, log(beta+/-sigma), was proved by the non-linear least-squares data 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.
Disic
J
J
Faculty of Science, Institute of Chemistry, P.O. Box 60, 34000 Kragujevac, Yugoslavia.
Trifunovic
S
S
Grujic
S
S
Djurdjevic
P
P