The study on the interaction between Tb(III) and ligand in Tb–acetylsalicylic acid complex and fluorescence mechanism

In this paper, a luminescent complex of terbium–acetylsalicylic acid (Tb-ASA) was studied for the first time using combination of the quantum chemical calculation, fluorescence spectroscopic method and X-ray photoelectron spectroscopy (XPS). The results from the quantum chemical calculation indicated that it is possible for the energy-transfer from ASA to Tb (III); Fluorescence spectroscopy demonstrated that there is an intramolecular energy-transfer from ASA to Tb with the efficiency (III) of about 87.9% under an excitation at 308 nm. The XPS indicated that the coordinate covalent bond between Tb and O existed in the complex of Tb-ASA leads to the effective energy transfer from ASA to Tb (III) because the energy transfer rate may be improved with reducing the distance between the ligand and Tb (III). The results will have important values for the studies of this type of complexes.