Enhancement of the intrinsic fluorescence of acridine and its induced circularly polarized luminescence (CPL) in ionic two-coordinate coinage metal complexes

Abstract

The intrinsic π–π* fluorescence of acridine is weak due to the deactivation via coupling with a close-lying non-emissive ¹n–π* state. By employing the lone pair of acridine to establish coordination bonds in a series of two-coordinate Cu(I) and Ag(I) complexes, significantly enhanced intrinsic fluorescence of acridinyl is observed with a photoluminescent quantum yield (Φ_PL) approaching 50%. Using chiral camphorsulfonate counterions, the cationic complex was induced to emit circularly polarized fluorescence with a reasonable g_lum of 5 × 10⁻³.