Extraction of Nickel (II) from aqueous solution by use 2-[(4-Chloro-2-methoxy phenyl)azo]-4,5di phenyl imidazole

Abstract

Dependence on sensitivity and selectivity for imidazole compounds to transition metal elements as cations ,extracted Ni+2 ions from aqueous solutions by solvent extraction method to produce ion pair association complex by use ligand 2-[(4-Chloro-2-methoxy phenyl)azo]-4,5-di phenyl imidazole (4-ClMePADPI).The study demonstrated the optimum conditions for extraction was (pHex=9) ,shaking time was (15-minute) and Ni+2 ions concentration was (70μg)(2.38×10-4M),the organic solvents effect on the extraction shows there is not any linear relation between distribution ratio (D) and dielectric constant (ε)for organic solvents used ,but shows there is an effect for the structure of organic solvent on the extraction ability and stability of ion pair complex extracted ,from other hand the stoichiometric study shows the more probable structure for ion pair complex extracted was (1:1) (metal:ligand) [Ni(4-ClMePADPI)]+2SO4-2. Thermodynamic study illustrated the complexation reaction between Ni+2ion and ligand (4- ClMePADPI ) was exothermic