Synthesis and fluorescence properties of lanthanide (III) perchlorate complexes with...

A ligand with double sulfinyl groups, naphthyl-naphthalinesulphonylpropyl sulfoxide(dinaphthyl disulfoxide, L), was synthesized by a new method and its several lanthanide (III) complexes were synthesized and characterized by element analysis, molar conductivity, coordination titration analysis, IR, TG-DTA, (1)HNMR and UV spectra. The composition of these complexes, were RE(2)(ClO(4))(6).(L)(5).nH(2)O (RE = La, Nd, Eu, Tb, Yb, n = 2 approximately 6, L = C(10)H(7)SOC(3)H(6)SOC(10)H(7)). The fluorescent spectra illustrated that the Eu (III) complex had an excellent luminescence. It was supposed that the ligand was benefited for transferring the energy from ligand to the excitation state energy level ((5)D(0)) of Eu (III). The Tb (III) complex displayed weak luminescence, which attributed to low energy transferring efficiency between the average triplet state energy level of ligand and the excited state ((5)D(4)) of Tb (III). So the Eu (III) complex displayed a good antenna effect for luminescence. The phosphorescence spectra and the relationship between fluorescence lifetime and fluorescence intensity were also discussed.