Liquid-liquid extraction of metal ions, DFT and TD-DFT analysis for some pyrane derivatives with high selectivity for Fe(II) and Pb(II)

Liquid-liquid extraction of metal ions using pyrane derivatives was studied. Fe2+, Zn2+, Cu2+, Co2+, Cd2+, Ni2+, and Pb2+ were extracted from the aqueous phase into the organic phase and the extractability for each metal was determined by atomic absorption. Interestingly, a competitive extraction was also investigated and then examined at different pH in order to explore the effect of the different substituent groups on metal extraction. We found high selectivity towards Fe2+ (91.8%) and Pb2+ (90.7%). In addition, geometry optimizations of the ground and excited-states of the selective ligands in order to get better insight into the geometry and the electronic structure were carried out by DFT and TD-DFT calculations.