Enantiopure Tetraphenylethylene-Based Metallacages with Bright Circularly Polarized Luminescence

The development of chiral materials that exhibit both high photoluminescence quantum yields (PLQYs) and large luminescence dissymmetry factors (g_lum) remains a formidable challenge in photonic materials. Herein, the preparation of enantiopure tetraphenylethylene (TPE)-based metallacages that display a remarkable combination of high PLQY (20.6%) and a large g_lum value of 0.12 in the solid state is reported. The efficient chirality transfer from the Pt(II) nodes to the prochiral TPE ligands is facilitated by rigidification through metal-ligand coordination, which suppresses the free rotation of the aryl groups and enables intense emission of the metallacages. The dense intermolecular packing of the metallacages in the crystalline phase contributes to a large g_lum of 0.12, which is among the highest reported values for metallacage-based systems. This study presents a straightforward strategy for constructing enantiopure metallacages with both intense circularly polarized luminescence and large dissymmetry factors, advancing design principles for high-performance chiral photonic materials.