Effect of ionic strength on complex equillieria between lanthanide metal ions and substituted pyrazole in dioxane -water mixture

G.H. MURHEKAR*, M.L. NARWADE and A.R. RAUT

Department of Chemistry, Government Vidarbha Institute of Science and Humanities, Amravati - 444 604 (India).

Received on August 08, 2009 and accepted on October 15, 2009

ABSTRACT

The proton ligand stability constants of 3 (4’-chlorophenyl) - 4- benzoyl -5 (2-hydroxy phenyl) pyrazole (L) and metal ligand stability constants of Pr (III), Nd (III) and Sm (III) complexes have been investigated at 0.02, 0.04, 0.06, 0.08 and 0.1 M ionic strength in dioxane-water mixture, pH metrically. From the values of pK and logK, the values of thermodynamic constants at zero ionic strength can be calculated. The value of pK and logK are found to be decreased with increasing ionic strengths of 1M KNO3 solution

Keywords : Stability constants, ionic strength, lanthanide metal ions, pyrazole.