Synthesis, characterization and spectroscopic studies of two new schiff-base bithienyl pendant-armed 15-crown-5 molecular probes

Two new ligands provided with a 15-crown-5 as a receptor unit and bithiophen unit as an emissive probe have been synthesized and characterized in order to evaluate the coordination capabilities and their sensor effect. Ligand L1 presents an aromatic crown ether moiety that is directly linked to the imine-2,2′-bithiophene π–conjugated system, and ligand L2 is constituted by an aliphatic crown ether moiety that is linked to the same imine-2,2′-bithiophene system through a methylene unit. Solid metal complexes of Ni(II), Pd(II), Hg(II) and Na(I) have been synthesized using both macrocyclic compounds, and have been studied in solution in the presence of the same metal ions. All solid compounds have been characterized by common analytical and spectroscopic techniques. The sensorial effect has been studied using absorption, emission and MALDI-TOF-MS spectroscopies.