Modulating Magnetoelectric Dipole by Salt-Bridge Hydrogen Bonds Assembly to Amplify Circularly Polarized Luminescence

Lanthanide ions are promising for high-performance circularly polarized luminescence (CPL) materials due to the significant transition magnetoelectric dipole properties. Consequently, controlling the magnetoelectric dipole moments is a key for enhancing their CPL performance. Here, we assembled a chiral europium assembly (Eu₂ assembly) from an Eu(III) complex, which manipulated the structure of complex monomer and modulated the orientation and magnitude of the magnetoelectric dipole moments, leading to a dramatic enhancement in CPL performance. The resulting material exhibits a high quantum yield of 42% (up from 27%) and a luminescence dissymmetry factor of 0.106 and 0.0857, representing a 10-fold enhancement over the precursor complex (0.0113 and 0.00907). This work not only establishes a clear structure-dipole-performance relationship but also provides a general strategy for developing high-performance lanthanide-based CPL materials.