Abstract
Molecules bearing -keto-enol functionality are potential candidates for coordination chemistry. Reported herein is the first synthesis and use of a novel designed ligand based on -keto-enol group embedded with pyridine and thiophene moieties. The product was prepared in a one-step procedure by mixed Claisen condensation and was characterized by EA, m/z, FT-IR, (H-1, C-13) NMR and single-crystal X-ray diffraction analysis. The new structure was grafted onto silica particles to afford a chelating matrix which was well-characterized by EA, FT-IR, solid-state C-13-NMR, BET, BJH, SEM and TGA. The newly prepared organic-inorganic material was used as an adsorbent for efficient solid-phase extraction (SPE) of Cu(II), Zn(II), Cd(II) and Pb(II) from aqueous solutions and showed a capture capacity of 104.12 mgg(-1), 98.90 mgg(-1), 72.02 mgg(-1), and 65.54 mgg(-1), respectively. The adsorption capacity was investigated, in a batch method, using time of contact, pH, initial concentration, kinetics (Langmuir and Freundlich models), and thermodynamic parameters (G degrees, H degrees and S degrees) of the system effects.