EVALUATE THE EFFECT OF SUBSTITUTED THIOCARBAMIDO-1-NAPHTHOL ON STABILITY CONSTANT BY USING Cu(II), Cd(II) AND Cr(III) METAL IONS IN 70% ETHANOL-WATER MIXTURE

The present work deals with the study of proton -ligands and metal- ligands stability constant of 5-pchlorophenylthiocarbamido-1-naphthol and 5-p-tolylthiocarbamido-1-naphthol with Cu (II), Cd(II) and Cr(III) metal ions at 0.1 M ionic strength in 70 % ethanol-water mixture by Irving?Rossotti titration technique. 5-pchlorophenylthiocarbamido -naphthol and 5-p-tolylthiocarbamido-1-naphthol form 1:1 complexes by interacting with Cu(II), Cd(II) and Cr(III) metal ions were found in present work. The values of proton-ligand stability constant (pK) and metal-ligand stability constants (log k) were evaluate and compared from resultant data. The effect of substituents were also studied from resultant estimated data on pK and log K. Keywords: 5-p-chlorophenylthiocarbamido-1-naphthol, 5-p-Tolylthiocarbamido -1-naphthol, stability constant, pH-metry.