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

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 (gem) 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 degrees C. A high CPP-active material is developed by using chiral co-assembled strategy from an achiral robot-like nematic Pt(II) metallomesogen and anchored binaphthyl-containing chiral inducers. All fresh spin-coated films are CPP-silent before thermal annealing, while exhibits the strongest CPP emission (lambda em = 642 nm). image