Chelation and extraction of copper(II) with 5-pyrazolone-based Schiff bases

Abstract

Copper(II) chelates of the Schiff bases (H₂L), obtained by condensation of 4-butyryl-3-methyl-1-phenyl-pyrazoline-5-one (HBMPP) with o-phenylene diamine (H₂L¹) and p-phenylene diamine (H₂L²), have been prepared and characterized by elemental analyses, thermogravimetric analyses, magnetic measurements, diffuse reflectance spectra, IR and mass spectra, and conductance measurements. The extractability of copper(II) with H₂L in chloroform was examined. Effective extraction was observed with 1 × 10⁻³ mol dm⁻³ of ligands at pH 6.5 using H₂L¹ and pH 7.0 using H₂L². The nature of the extracted species was ascertained by the slope analysis method. The ligand can effectively be used in solvent extraction of copper(II) from aqueous phase to organic phase.

Keywords:

• Ligands
• Extraction
• Schiff bases
• 5-Pyrazolones
• Copper(II)

Acknowledgments

The authors wish to thank Dr H.S. Patel, Head, Department of Chemistry, for his constant encouragement and necessary facilities. One of the authors (NJP) gratefully acknowledges financial support from UGC, New Delhi, India, under UGC scheme of minor research project (letter no. F30-91/2004(SR), dated 28.10.2004).