Abstract

A set of imino-phenol ligands L1–L8 were synthesized and fully characterized by spectroscopic methods (NMR, FTIR, UV/Vis and MS) with good yields (≥60%). Ligands L1–L8 were used for the preparation of copper complexes C1–C8 from their reactions with Cu(OAc)2·H2O in a ligand/Cu(II) molar ratio of 2:1. Then, a set of solvent-extraction (SX) experiments for Cu(II) were performed at room temperature for 60 min at pH 4.5, and L8 exhibited the highest value (75%) for Cu(II) extraction. Cu(II) stripping studies were then performed at 50 °C for 60 min with L1 and L5–L7 at pH 3.0 and L8 at pH since these ligands decompose at lower pH values. Notably, L1 and L6 achieved the best results for the stripping step, yielding 46% and 47% extraction, respectively. On the other hand a set of competitive extraction studies were performed with different divalent metal ions (Cu(II), Co (II), Ni(II) and Mn(II)) using L8 and good extraction values (57–75%) were obtained for all of the metal ions at pH 4.5. Finally, extraction/stripping selectivity experiments were performed with the aforementioned metal ions using L8 and L1. L8 exhibited good selectivity for Cu(II) (75%) in the extraction process at pH 4.5, whereas L1 produced moderate values of selectivity (approximately 60%) for all of the divalent metal ions at pH 3.0 in the stripping process.