Doped Luminescent Lanthanide Coordination Polymers Exhibiting both White-Light Emission and Thermal Sensitivity

Multifunctional lanthanide coordination polymers (CPs) have the advantages of acting in two or more fields simultaneously. Herein, two single lanthanide CPs, formulated as LnL(D/L-Hlac)(H₂O)₂·0.5H₂O (Ln = Eu (1), Tb (2); H₂L = 4,4'-(pyridine-3,5-diyl)dibenzoic acid) and their doped lanthanide analogue Tb_0.9373Eu_0.0627L(D/L-Hlac)(H₂O)₂·0.5H₂O (3) were prepared through hydrothermal methods. Luminescence measurements reveal that 1 displays red photoluminescence and its Commission International ed'Eclairage (CIE) coordinates are almost invariant in the temperature range from 80 to 300 K, while the emission color of 2 changes from yellow to green and its CIE coordinates change from (0.36132, 0.56365) at 80 K to (0.30448, 0.45566) at 300 K. Significantly, 3 not only displays white-light emission with CIE coordinates of (0.32999, 0.33406) but also exhibits a thermal sensitivity of 2.27% K^-1 at 230-300 K. The obviously larger thermal sensitivity in 3 in comparison to that of 1.07% K^-1 for 2 demonstrates that lanthanide CPs with both a heat-sensitive fluorescent thermometer and high-efficiency white-light emission can be expected by doping Eu(III) ions into Tb(III)-based CPs.