Study on Stability of Ternary Complexes [Pd(phen)(gnapa)]~+ in Mixed Medium H_2O/C_2H_5OH

The stability constant lg K of the Pd(Ⅱ)-phen-gnapa Ternary Complexes has been determined,when the volume fraction of the organic solvent C2H5OH is 10 %,20 %,30 %,40 % and 50 %,respectively,at 37 ℃ and I=0.1 NaCl, by pH potential titration.The relevant characteristic constants,Δlg K,of the ternary complexes have been calculated.With the Pd(Ⅱ)-phen-gly ternary complexes being comparable system,The aromatic ring stacking percent has been calculated.The aromatic ring stacking percent is max,when the volume fraction of the organic solvent,C2H5OH is 30 %,that shows the stability of the ternary Complexes is influenced by the solvent composition.