Solvent extraction of Cobalt (II) from aqueous solutions by new ligand 2-[(4-Chloro-2-methoxy phenyl) azo] -4,5- diphenyl imidazol

The solvent extraction of Co(II) by used a 2-[(4-Chloro -2-methoxy phenyl ) azo ]-4,5- diphenyl imidazol ( 4-ClMePADPI ) have been studied, The results shows that the optimum pH extraction was (pHex=9) ,and the optimum shaking time was 10min. as well as Co+2concentration was 30μgCo2+ ( 1.018x10-4M) ,The stoichiometry study shows the more probable structure of ion pair complex extracted was (1:1) (Metal:Ligand) Co+2:(4-ClMePADPI) SO4-2 , organic solvent effect appear distribution ratio (D) for extraction increase with decrease of dielectric constant and higher distribution ratio(D) get with carbon tetra chloride may be decreasing dielectric constant for organic solvent help to destroy the hydration shell about metal cation Co+2 and giving free cation to enhancement the ability of coordination between ligand molecules and metal cation, thermodynamic study shows the reaction was exothermic reaction and the reaction was entropic region .