Synthesis and characterization of bright green terbium coordination complex derived from 1,4-bis(carbonylmethyl)terephthalate: Structure and luminescence properties

A photoluminescent terbium (Tb) complex involving a novel benzoic-acid compound with a unique coordinated structure, namely 1,4-bis(carbonylmethyl)terephthalate (BCMT), has been designed and synthesized. The new coordinate structure and energy-transfer mechanism between the ligand and Tb(III) ions were investigated in detail. The results demonstrated that the BCMT–Tb(III) complex shows strong fluorescence intensity (4   ×   10 6   a.u.) and long fluorescence lifetime (1.302   ms), owing to the favorable degree of energy matching between the triplet excited level of the ligand and the resonant level of Tb(III) ions. Based on the analysis of three-dimensional luminescence spectra , the as-prepared Tb(III) complex can be effectively excited in the range of 250–310   nm, and it shows high color purity, with a bright green appearance.