Emission Properties of Eu(III) Complexes Containing Arsine and Phosphine Ligands with Annulated Structures.

In this study, we synthesized Eu 3+ complexes containing arsine and phosphine oxides with annulated structures as the antenna ligands. The type of bridging in the annulated structures controlled the energy level of the triplet excited state and the intersystem crossing efficiency, leading to different emission properties. Eu 3+ complexes bearing the arsine oxides showed a higher intensity ratio of electric/magnetic dipole transitions and energy-transfer efficiency than the complexes with the corresponding phosphine oxides.