Fluorescence enhancement of samarium (III) perchlorate by 1,10-phenanthroline on Phenylnaphthoylmethyl sulfoxide complex and luminescence mechanism

A novel ligand, Phenylnaphthoylmethyl sulfoxide, was synthesized by a new method. Its novel binary complex, SmL5·(ClO4)3·2H2O, and the ternary complex, SmL4·L′(ClO4)3·2H2O, had been synthesized (using Phenylnaphthoylmethyl sulfoxide as the first ligand L, 1,10-phenanthroline as the second ligand L′). The complexes were characterized by element analysis, coordination titration, molar conductivity, IR, TG-DSC, 1HNMR and UV spectra. Their fluorescence emission mechanism, fluorescence intensities and phosphorescence spectra of the two ligands were also investigated by comparison. Fluorescent spectra illustrated that the ternary rare-earth complex presented stronger fluorescence intensity than the binary rare-earth complex in such material. The strongest characteristic fluorescence emission intensity of the ternary system was 1.81 times as strong as that of the binary system. By the analysis of fluorescence and phosphorescence spectra, it was found that the Phenylnaphthoylmethyl sulfoxide and phen had the advantage to absorb and transfer energy to Sm (III) ions effectively, and then the complexes emitted the characteristic fluorescence of Sm (III) ions. The phosphorescence spectra and fluorescence lifetime of the complexes were also measured. -- Highlights: • A novel ligand, Phenylnaphthoylmethyl sulfoxide, has been synthesized. • Its novel ternary complex and the binary complex have been synthesized. • The fluorescence emission intensity of ternary rare earth complex exhibit obvious enhancement. • The fluorescence emission mechanism and phosphorescence spectra are also investigated