The stability constants of the ternary mixed ligand complexes Pt(Phen)(CA) +(Phen=1,10 Phenanathroline,CA=carboxylate Ligands) were determined by potentiometric pH titration in aqueous solution and in 30～90%(V/V) aqueous ethanal(I=0.1mol·L -1 ,KNO 3;25℃).The difference of stability among the different complexes was compared and discussed,and the percentages of the stacked isomers in the ternary mixed ligand complexes Pt(Phen)(PCA) +(PCA=2 phenylacetate and 3 phenylpropionate) was calculated.The experimental results indicate that the extent of the intramolecular aromatic ring stacking interaction in the ternary mixed ligand Pt(Phen)(PCA) + complexes depends on the polarity of the solution.The weaker the polarity of the solution,the more notable the intramolecular aromatic ring stacking interaction,the larger the percentage of the stacked isomers in the ternary complexes,and the more stable the ternary mixed ligand complexes.
