Strong Circularly Polarized Phosphorescence of Achiral Pt(II) Metallomesogen Induced by Using a Chiral Co‐Assembly Strategy

Abstract The high planarity and heavy‐atom effect of Pt(II) metallomesogens promote their stacking in the aggregated state and highly efficient phosphorescence. This makes them promising candidate materials for circularly polarized phosphorescence (CPP) triggered by using a chiral co‐assembly strategy. In this paper, a nematic phase, achiral robot‐like Pt(II) metallomesogen (TFPt) is synthesized, which combines two anchored chiral binaphthyl inducers (R/S1 or R/S2) to construct cholesteric liquid crystal (N*‐LC) co‐assemblies (R/S1)_n‐(TFPt)_1‐n and (R/S2)_n‐(TFPt)_1‐n via intermolecular interactions. The resultant N*‐LC chiral co‐assemblies (R1)_0.03‐(TFPt)_0.97 and (R2)_0.03‐(TFPt)_0.97 exhibit the strongest CPP emission with high dissymmetry factors (g_em) of up to 0.18 and 0.27, respectively, stemming from the formation of regular helical nanofibers on spin‐coated films via co‐assembly process after thermal annealing at 165 °C.