Mechanism of Protonation in Complex Fromation of Cu(Ⅱ) Ternary Com- plexes: pH Metric Study

摘要

Mixed ligand formation constants of Cu(Ⅱ) complexes at 1:1:1 optimum molar concentration of metal, primary ligand (A) and secondary ligand (L) are determined in aqueous medium at constant ionic strength m=0.2M dm~(3-) at 30 +- 0.1℃. The difference between the stability of ternary complexes and the corresponding binary complexes has been expressed in terms of parameter Dlog K_T. the variation of Dlogl_T values have been explained in terms of M → Lπ interaction, size of chelating ring and steric factors. Stability constants have been evaluated and discussion interns of π-basicity of ligand, statistical and stereo chemical phenomenon. A mechanism of protonation and Cu(Ⅱ) ternary complex formation is suggested.