Constructing Lanthanide Coordination Polymers for Luminescent Sensing of D ₂ O and CH ₃ OH Using Hierarchical Regulation Strategy from Structure to Function

Lanthanide coordination polymers (LnCPs) have great potential in luminescent sensing and other fields due to their unique f-orbital properties. While high coordination numbers bring about structural diversity, they also pose difficulties in structural regulation. It is particularly important to achieve functional structural regulation of lanthanide coordination polymers and minimize the unpredictability of structural synthesis and functional research. Meanwhile, developing luminescent sensing properties for lanthanide elements other than Eu and Tb and expanding their application fields remains challenging. The rapid identification of CH₃OH and C₂H₅OH, as well as H₂O and D₂O, is of great significance for human ecological health, industry, and scientific research. In this work, two types of LnCPs (L1-Ln-1 and L1-Ln-2) were synthesized by a solvent-controlled method using sodium isophthalic acid sulfonate as ligand, and Eu/Tb and Sm/Tb-doped dual-emitting materials were prepared. Among them, L1-Eu0.2Tb0.8-1 and L1-Sm0.8Tb0.2-1 can achieve visual differentiation between CH₃OH and C₂H₅OH through changes in luminescence intensity ratio and CIE chromaticity coordinates; L1-Eu0.14Tb0.86-2 with excellent water stability can quantitatively and qualitatively detect the content of D₂O in the H₂O-D₂O mixed system, and achieve visible luminescence changes from green to orange with a detection limit of 5 × 10⁻⁵ (v/v), and has good cyclic performance. The PMMA composite films prepared from both types of materials demonstrate potential for portable and stable practical applications.