Abstracto

Metal Ligand Stability Constant of Substituted 3,5-Diaryl Isoxazolines Complexes in 70% Dioxane Solvent Media

S. A. Thorat and S. D. Thakur

The complex formation between Pr(III) & Sm(III) metal ions and 3-(2-hydroxy-3-nitro-5-methylphenyl)-5-(3- nitrophenyl)isoxazoline L1, 3-(2-hydroxy-3-nitro-5-methylphenyl)-5-(4-chlorophenyl) isoxazoline L2, 3-(2-hydroxy-3-nitro- 5-methylphenyl)-5-(2-furyl)isoxazoline L3 have been studied at 0.1 M ionic strength (26 ± 0.1oC) in 70% dioxane water mixture by Bjerrum method as adopted by Calvin & Wilson. It is observed that Pr(III) & Sm(III) metal ions form 1:1 & 1:2 complexes with ligand L1, L2 & L3. The data obtained were used to estimate & compare the values of proton ligand stability constant (pK) & metal ligand stability constant (log K). From estimated data (pK & log K), the effect of substituents were studied.