A highly efficient lanthanide coordination polymer luminescent material for the multi-task detection of environmental pollutants

Abstract

It is challenging to explore novel-structure lanthanide coordination polymers (Ln-CPs) for sensing environmental pollutants. Herein, we designed and synthesized an organic bridging linker 3-(carboxymethoxy)-1-(carboxymethyl) pyrazole-4-carboxylic acid (H₃ccpc), and then successfully prepared and characterized a novel Ln-CP, namely [Tb₂(ccpc)₂(H₂O)₆]·1.5H₂O (ccpcTb). Structural analysis indicates that ccpcTb exhibits a two-dimensional structure, in which Tb ions are in an eight-coordinated environment. The photoluminescence performance of ccpcTb was discussed in detail. The ccpcTb displays bright green luminescence and behaves as a multi-responsive luminescent sensor toward Fe³⁺ ions, Cr₂O₇²⁻ ions and 2,4,6-trinitrophenol with high selectivity and low detection limits. Furthermore, the possible luminescence sensing mechanisms have been addressed in detail. The luminescence quenching mechanism of sensing Fe³⁺ and Cr₂O₇²⁻ is attributed to the energy competitive absorption, while that of sensing TNP is due to the synergistic effect of energy competitive absorption and photo-induced electron transfer.