Symmetry‐Breaking Directed Assembly in Achiral Point Groups for Circularly Polarized Room‐Temperature Phosphorescence

Abstract Very recently, considerable attention has been given to pure organic circularly polarized room‐temperature phosphorescent (CP‐RTP) materials due to their unique photophysical properties. However, the directed construction of optically active phosphorescent signals within achiral systems remains a formidable challenge. In this study, two achiral crystals, 2CN4S and 2F4S , belonging to the achiral point groups 2/ m and , exhibit strong CP‐RTP emission with high photoluminescence dissymmetry factors ( g lum ) up to 5.5 × 10 −2 (543 nm) and 4.3 × 10 −2 (550 nm), respectively. This phenomenon is attributed to the intrinsic mirror‐antiparallel molecular conformations induced by the targeted substitution of cyano/fluoro groups, which spontaneously assemble into symmetry‐breaking helical superstructures through synergistic C─H···N hydrogen bonding and π – π interactions. This work not only establishes a novel approach for CP‐RTP material design but also overcomes structural constraints in optically active materials within achiral point group systems.