Highly Improved Quantum Yields of Dehydrated Lantha-nide-based Coordination Polymers as Luminescent Thermometer in Low Temperature Range

High quantum yields and energy transfer efficiency are favored by luminescent thermometers. In this work, dehydration process has been applied to remove 12 coordinated and isolated water molecules of 1 dimensional chains [Ln2(mip)3(H2O)84H2O]∞ (abbreviated as Ln2MIP). The overall quantum yields of Tb3+ has been improved to 80% from 47.5% after dehydration. In dehydrated Gd0.2Tb1.08Eu0.72MIP, the energy transfer efficiency between Tb3+ and Eu3+ reaches 96% from 27% that result in improving the overall quantum yields of Eu3+ from 8.4% to 13.1%. Compared with hydrated Gd0.2Tb1.08Eu0.72MIP, the dehydrated phase presents 1.5 times temperature sensing range between IEu/ITb and temperature with improved Sre (0.564 % K-1). At the same time, the intensity of Eu3+ at 618 nm displays excellent temperature sensing ability from 77 K to 300 K after dehydration with improved quantum yields