Synthesis, Liquid Liquid Extraction of Cu(II) and Pb(II) With DFT Calculation Studies of New Imidazo[1, 2-a]Pyridine Chalcones

New imidazo[1,2-a]pyridine-chalcones derivatives L₂ L₃ were prepared by condensation of one equivalent of 2-(phenyl) Imidazo[1, 2-a]pyridine carbaldehyde and one equivalent of an Acetophenone in the presence of KOH. These compounds were prepared in good yield (L₂:79%; L₃:85%) and fully investigated by ¹H and ¹³C NMR, and Mass spectroscopies, and new imidazo[1,2-a]pyridine (2-phenylimidazo[1,2-a]pyridin-8- ol(L₁)) was prepared by condensation of one equivalent of 2-aminopyridin-3-ol and one equivalent of 2- bromoacetophenonein EtOH.The compounds were used to extract different metal ions. Indeed (Zn²⁺, Cu²⁺, Cd²⁺ and Pb²⁺) were extracted from the aqueous phase into the organic phase and the extractability for each metal ion was determined by atomic absorption. The extractive affinity for Pb(II) is the high and is around 81% (L₃) and for Cu(II) is about 70% (L₁). Interestingly, the competitive extraction and the effect of pH were also investigated. We found a high selectivity towards Pb²⁺ (70%) for L₃, Cu²⁺ (65%) for L₁, respectively for each ligand. A back- extraction of Pb(II) and Cu(II) extracted with L₃ leads us to recover for Pb(II) 95% (using H₂SO₄) and for Cu(II) 96% (using HCl).In addition, geometry optimizations and excited-states of the ligands in order to gain a better insight into the geometry and the electronic structure were carried out by means of DFT calculations.The calculated electronic transitions are in agreement with experimental.