Abstract
The thermodynamics of complexation of the ligands 2,2'-oxybisethanamine (oden) and 2-(2-aminoethyl)aminoethanol (etolen) with the Ni2+ ion were re-investigated by glass electrode potentiometry and titration calorimetry at 25°C and in 0.5 mol dm-3 KNO3. In the case of the ligand etolen the data were consistent with previously reported complexes, Ni(etolen)2+ and Ni(etolen)22+, and associated stability constants. However, the enthalpies of complexation obtained here differ from those previously reported. Reasons for these discrepancies are discussed. For the ligand oden the data could only be explained by the inclusion of the ternary species Ni(oden)OH+ and Ni(oden)2OH+ in addition to the binary species Ni(oden)2+ and Ni(oden)22+. Thermodynamic parameters of complexation for these complexes are reported and compared with those of the etolen complexes.
Keywords: nickel; polyamines; stability constants; thermochemical parameters
view references (41)
No comments:
Post a Comment