Circularly Polarized Luminescent and Melt‐Processable Copper(I)‐Organic Glasses Based on 2,2′‐Bis(diphenylphosphino)‐1,1′‐binaphthyl

Abstract

ABSTRACT The melting and vitrification behavior of metal–organic materials endows them with high processability, enabling the formation of bulk solids with potential in optical applications. Nevertheless, obtaining metal–organic glasses with chiroptical properties, such as circularly polarized luminescence (CPL), remains challenging due to the limited thermal and mechanical stability of current chiral metal‐organic materials. Here, we report a pair of homochiral copper(I) cyanide complexes based on 2,2′‐bis(diphenylphosphino)‐1,1′‐binaphthyl (BINAP) that can be readily vitrified by either melt‐quenching or desolvation. Structural analysis reveals that vitrification disrupts only the intermolecular stacking of the complexes, while preserving the local coordination environment. The resulting melt‐quenched glasses are CPL‐active and exhibit yellow–orange triplet excited state decay via thermally activated delayed fluorescence (TADF) at room temperature, which is environment‐dependent due to an additional 3 BINAP↔ 3 (Cu→BINAP) CT (CT = charge transfer) equilibrium. Centimeter‐sized monoliths and thin films can be fabricated by molding and thermal annealing, highlighting their excellent processability. Moreover, the glasses can be recrystallized by solvent vapor treatment, which triggers distinct changes in luminescent properties. These results establish BINAP‐based copper(I) cyanide complexes as a versatile platform for the design of CPL‐active metal–organic glasses and point to their promise in optoelectronic applications.