White circularly polarized luminescence from a dual-component emitter induced by FRET between tetraphenylene and PDI derivatives†

Abstract

A chiral agent, TPE-ASP, incorporating aspartic acid as the chiral source and tetraphenylene derivatives as chromophores, was designed and synthesized. The chiral agent was self-assembled into regular spherical nanoparticles with a maximum luminescence asymmetry factor of |2.41 × 10⁻²| at 460 nm which is attributed to TPE-ASP. These nanoparticles can be co-assembled with a perylenediimide (PDI) derivative through electrostatic interactions, enabling the successful construction of a chiral light-harvesting system (C-LHS). The maximum Förster resonance energy transfer (FRET) efficiency (Φ_ET) of 94.7% was achieved at the optimal molar ratio of TPE-ASP to PDI. Fortunately, multicolour circularly polarized luminescence (CPL), spanning from blue to red, was successfully achieved with a two-component co-assembly system, and bright white CPL with CIE coordinates of (0.33, 0.32) was also obtained. Meanwhile, the average g_lum is |7.1 × 10⁻³| in the wavelength range of 400–700 nm. This discovery demonstrates the potential for spectral regulation through the two-component co-assembly strategy. It is significant for developing CPL devices with white light emission via the FRET process and also expands the functional range of chiral light-harvesting systems.