[show abstract][hide abstract] ABSTRACT: Chemical speciation of La(III), Ce(III), Pr(III), Nd(III), Sm(III), Gd(III) and Dy(III) complexes of creatinine was studied at 30ºC in 10%, 20%, 30%, 40%, 50%, 60% v/v dioxane-water mixtures and ionic strength was maintained as 0.2M (NaClO4). Titration data were obtained on the basis of Irving-Rossotti technique and data were pruned with computer program PKAS & BEST. The active forms of ligand are LH+ & L which were obtained with SPEPLOT. The dominant species of complexation are ML, ML2 and ML(OH)3. The stability of complexes that formed has increased with
increasing dioxane content. The change in stability constants with change in dielectric constant of medium is explained on the basis of cation solvating nature of cosolvent, specific solvent-water interaction, specific interaction of cosolvent with solute, electrostatic and non-electrostatic effects. The effects of systematic errors on stability constants are also studied. The order for these effects is dissolved carbon
dioxide > alkali > acid > ligand > metal. The trends of transportation and the availability of lanthanide ion for complexation can be explained on the basis of
distribution diagrams and the stability constants of complexes so formed.
RESEARCH JOURNAL OF CHEMISTRY AND ENVIRONMENT 01/2010; 14:45-49. · 0.64 Impact Factor