Photoactivatable Circularly Polarized Luminescence Materials With Tunable Afterglow Based on Two Zinc/Cadmium Complexes

ABSTRACT The strategies of chirality introduction and heavy‐atom effect have been applied to form two new circularly polarized luminescence (CPL) materials with afterglow, S‐Zn(BINAP)I ₂ and S‐Cd(BINAP)I ₂ (S‐BINAP = S‐1,1′‐binaphthyl‐2,2′‐diphenyl phosphine, abbreviated as S‐ 1 and S‐ 2 , respectively). In addition, simple, rapid, and large‐scale syntheses of S‐ 1 and S‐ 2 have been successfully achieved. S‐ 1 and S‐ 2 both show mononuclear structures built upon a bidentate S‐BINAP ligand and zinc or cadmium iodide. The films of S‐ 1 and S‐ 2 doped in PMMA exhibit room‐temperature phosphorescence (RTP) with intensity increased and lifetime elongated by UV irradiation, which may be attributed to oxygen‐depletion‐dependent photophysics. Moreover, S‐ 1 and S‐ 2 in PMMA films exhibited distinct afterglow phenomena lasting 2.2 s under UV irradiation. Both films exhibited good circular polarization luminescence (CPL) with g _lum being 2.7 × 10 ⁻³ and 5.1 × 10 ⁻³ , respectively. Furthermore, multicolor CPL with afterglow has been achieved via Förster resonance energy transfer (FRET) strategy upon doping a fluorophore of Rubrene. These materials demonstrate considerable promise for sophisticated security applications, including dynamic anti‐counterfeiting and high‐level information encryption.