Photoluminescence Properties and Stable Bipolar Resistive Switching Behavior of Two Eu(III)-Doped Hexameric Selenotungstates

Due to their structural versatility, selenotungstates have emerged as a prominent research focus in polyoxometalate (POT) chemistry. Two Eu(III)-doped hexameric selenotungstates with distinct architectures were synthesized via a one-pot synthetic strategy. Detailed structural investigations were prompted by their remarkable photoluminescence lifetimes of 759.8 μs (1) and 722.8 μs (2), significantly surpassing those of most reported Eu(III)-doped polyoxotungstates. Comparative analysis with literature precedents revealed a strong correlation between the luminescent behavior and the coordination environment of the Eu(III) centers. Furthermore, the compounds exhibited exceptional resistive switching performance at ambient conditions, with switching ratios of 1.03 × 10³ (1) and 3.67 × 10³ (2) that exceed most reported values for oligomeric POT-based systems. This work systematically investigates the structure–property relationships among molecular architectures, luminescent characteristics, and resistive switching behavior, providing experimental evidence for the design of new luminescent materials and molecular storage devices.