Synthesis, characteristic and intramolecular energy transfer mechanism of reactive terbium complex in white light emitting diode

A reactive Tb(III) complex with 2-aminobenzoic acid (2-ABAH) and acrylonitrile (AN) as ligands was synthesized. The structure of the complex was characterized by elemental analysis and Fourier transform infrared spectrometry (FT-IR). The results indicated that the ligands were coordinated with Tb(III) ion. Thermal gravity-derivative thermogravimetric (TG-DTG) analysis indicated that the complex kept stable up to 198 °C. Luminescence properties were investigated by UV-vis absorption spectra and fluorescence spectra. The results suggested that being excited at 361 nm, the complex exhibited characteristic emission of Tb(III) ion, revealing that the complex could be excited by 365 nm ultraviolet chip. The HOMO and LUMO, ΔE(HOMO–LUMO), molecular frontier orbital, and the singlet state and triplet energy state levels of the ligands were calculated at the B3LYP/6-31+G (d) level. The results indicated that intramolecular energy transfer mechanism followed Dexter exchange energy transfer theory. Both the calculation for excited state of ligand and energy transfer mechanism could provide the theoretical basis for the design of high luminescent materials of rare earth complexes with organic ligands.