Symmetry breaking of rare earth Eu( iii ) complexes with an achiral aromatic ligand: achieving strong emission and ultra-narrowband circularly polarized luminescence

Mononuclear Eu( iii ) complexes achieve a high luminescence quantum yield (91%) and ultra-narrowband circularly polarized luminescence (FWHM = 5 nm) via achiral π-conjugated ligand design and a spontaneous resolution crystallization process.