Circularly Polarized Organic Long-Persistent Luminescence from Polymer Films Doped with Chiral Cu(I) Complexes

Area of Science:

• Materials Science
• Organic Chemistry
• Photophysics

Background:

• Developing polymer materials with circularly polarized organic long-persistent luminescence (CP-OLPL) is a significant challenge.
• Existing OLPL systems often rely on complex donor-acceptor doping strategies.

Purpose of the Study:

• To create novel polymer-based materials exhibiting CP-OLPL properties.
• To investigate the mechanism behind ambient OLPL and CP-OLPL emissions in polymer matrices.

Main Methods:

• Embedding a copper(I) complex (rac-NDP-CuCl) into polymethyl methacrylate to create an OLPL system.
• Replacing the racemic complex with its enantiomers (R-NDP-CuCl and S-NDP-CuCl) to achieve CP-OLPL.
• Analyzing phosphorescence quantum yield, emission duration, and circular polarization asymmetry factors.

Main Results:

• The polymer system demonstrated a high phosphorescence quantum yield (64.0%) and emission duration over 3 hours.
• The first polymer-based CP-OLPL materials were successfully developed using enantiomeric copper(I) complexes.
• Asymmetry factors for circularly polarized phosphorescence and OLPL reached up to 4.79 × 10⁻³ at room temperature.
• The mechanism involves photoinduced metal-to-ligand charge transfer stabilized within the polymer matrix.

Conclusions:

• This work presents a novel approach for designing ambient OLPL and CP-OLPL materials.
• The findings offer new insights into molecular design for persistent luminescence in polymers.
• This opens promising avenues for developing advanced polymer-based CP-OLPL systems.