Extraction of Zn(II) by use 2-[4-chloro-2-Methoxy phenyl azo]-4,5-diphenyl imidazole

By use complexation selectivity for azo compounds with transition metal elements as cations in aqueous solutions, extracted Zn(II) ions by solvent extraction method as ion pair complex by using 2 -[4-chloro-2-Methoxy phenyl azo]-4,5-diphenyl imidazole [4-ClMePADI]. The study shows the optimum pHex for extraction of Zn2+ ions from aqueous solution was (pHex = 8), also the optimum concentration of Zn2+ ions in aqueous solution was (80 μg /10 mL) (1.223×10-4M) which is giving higher distribution ratio (D), in side of kinetic for extraction method the study shows that the optimum shaking time for the two layers was (15 min.), the study about effect of organic solvent used in extraction method demonstrate there is not any linear relation between distribution ratio (D) and dielectric constant of organic solvents used as well as shows the effect of organic solvent structure on the extraction method, from other hand the stoichiometric study shows the more probable structure of ion pair complex extracted for Zn2+ ions was (1 : 2) (metal : ligand) [Zn(4- ClMePADI)2]2+(Cl-)2, thermodynamic study illustrated the complexation reaction between Zn2+ ions and ligand [4-ClMePADI] was endothermic. Key word: Solvent extraction, Zinc.