Synthesis and Photoluminescent Properties of Lanthanides Acetoacetanilide Complexes

This work reports on the photoluminescent properties of three new lanthanide complexes with acetoacetanilide (aaa), a beta-diketonate ligand. The complexes have the general molecular formulae [RE(aaa)(3)(H2O)], they are soluble in organic solvents such as ethanol and chloroform and insoluble in water. The energy of the triplet state was determined at about 4,700 cm(-1) higher than the D-5(4) emitting level of the Tb(III) ion, leading to an absolute quantum yield of 22 % for the [Tb(aaa)(3)(H2O)] complex. The photoluminescent properties were studied and the luminescence parameters of the [Eu(aaa)(3)(H2O)] complex were experimentally determined. The photostabilities of the complexes under continuous UV irradiation were measured and the data indicate low stability of the [Tb(aaa)(3)(H2O)] complex when the system is excited at the band attributed to energy transfer from the ligand to terbium(III) ion. However, its photostability is significantly improved under inert atmosphere.