High-Performance Circularly Polarized Phosphorescence by Confining Isolated Chromophores with Chiral Counterions

Abstract

Organic room-temperature phosphorescence (RTP) featuring circularly polarized luminescence (CPL) is highly valuable in chiroptoelectronics, but the trade-off issue between luminescence efficiency (Φ) and dissymmetry factor (g_lum) is still challenging to be solved. Here, chiroptical ionic crystals (R/S-DNP) are constructed through ionization-induced assembly, in which isolated chromophore of carboxylic anion is tightly confined by the surrounding chiral counterions. The long-range ordered and chiral counterions with asymmetric stacking are closely connected with isolated chromophores for molecular assembly via high-density electrostatic interactions, thus enabling the simultaneous realization of excellent single-molecule RTP emission and efficient chirality transfer. The synchronous enhancement of Φ_P and g_lum is further achieved as 43.2% and 0.13, respectively. In view of the excellent CPL performances, the ionic materials hold the promising chiroptical encryption via programmable control in an electric-driven circularly polarized phosphorescent device. This result not only makes deeper insights into the relationship between the structure and chiral RTP property but also provides a guide to developing highly efficient chiroptical materials for potential applications.