Luminescent and Magnetic Properties of Lanthanide-Thiophene-2,5-dicarboxylate Hybrid Materials

Abstract

Three lanthanide-thiophenedicarboxylate hybrid compounds, [(Eu2(TDC)3(CH3OH)2·(CH3OH)] (1), [(Yb2(TDC)3(DMF)(H2O)·(CH3CH2OH)] (2), and [(Tb2(TDC)3(H2O)4] (3) (where TDC is deprotonated thiophene-2,5-dicarboxylic acid and DMF is dimethylformamide), have been prepared by a hydrothermal method. The TDC ligands exhibit two unprecedented (κ2-κ1-μ2)−(κ1-κ1)−μ5 and (κ2)−(κ2)−μ2 coordination modes as well as other various modes. Structure analysis reveals that 2,5-thiophenedicarboxylic acid play a versatile role toward different lanthanide ions to form three-dimensional inorganic−organic hybrid frameworks. The luminescence experiments show that Eu(III) and Tb(III) compounds exhibit typical luminescence in the visible region, while the Yb(III) compound emits characteristic near-infrared luminescence in the solid state even with the coordinated water molecules. Besides luminescence, the Tb(III) compound also shows weak ferromagnetic behavior, which indicates that it is acting as a dual function material.