Conjugated Microporous Polymers Doped with Rare Earth Ions: Synthesis, Characterization and Energy Transfer

In order to study the energy transfer between the conjugated polymer and rare-earth ions, a series of conjugated microporous polymers (CMPs) CMP-COOH@M (M=Eu³⁺ , Tb³⁺ , La³⁺ , and Sm³⁺ ) with different kinds of rare-earth ions was synthesized, in which the conjugated networks can effectively improve the luminescence of rare-earth ions due to the effective energy transfer from the CMP network to the rare-earth ions centers. The absolute quantum yield of CMP-COOH (Φ_FL ) is 29.1 %, while the Φ_FL value of CMP-COOH@Eu, CMP-COOH@Tb, CMP-COOH@La, and CMP-COOH@Sm is 9.4, 8.6, 14.3, and 9.1 %, respectively. This result indicates that the quantum efficiency of CMPs network is 1/2-1/3 of the original one due to the coordination of rare earth ions, that is, rare-earth ions can be recognized as fine modulators to adjust the emission color of CMPs in a controlled manner through controlling the species of rare-earth ions.