Abstract
Study of Proton-Ligand and Metal-Ligand Stability Constants of Some Substituted Isoxazolines
S. R. Dighade1, M. L. Narwade2* and M .M. Chincholkar2*
Abstract:
The interactions of Cu (II) and Ni (II) metal ions with I) 3-(2-hydroxy-5-methylphenyl)-4-benzoyl-5(3-nitrophenyl)-isoxazoline (Ligand No.1), ii) 3-(2-hydroxy-5-methylphenyl)-5(3-nitrophenyl)isoxazoline (Ligand No.2), iii) 3-(2-hydroxy-5-methylphenyl)-5-(4-methoxyphenyl)-isoxazoline (Ligand No.3) have been studied at 0.1 M ionic strength. It is observed that Cu(II) and Ni(II) metal ions from 1:1 and 1:2 complexes with L1,L2 and L3 (Substituted isoxazolines). The ligands L2 and L3 are more chelating agents than L1 synthesised from 3-aroylflavanone. The substituted isoxazolines show formation of stepwise complexes. The order of proton-ligand stability constant is as pk L3> pk L2> pk L1. The data obtained pK and logK are used i) to see the effect of substituents ii) to check the validity of logK = a pK + b. Here proton-ligand and metal-ligand stability constants have been studied pH-metrically by Calvin-Bjerrum titration technique.
Keywords:Proton-ligand and metal ligand stability
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