Topological Engineering From Non-Emissive Chiral Metallomacrocycle to Interlocked Architecture for Strong Circularly Polarized Luminescence.

Interlocked architectures are crucial for stabilizing specific conformations to achieve superior performance. Herein, we proposes a vacant π-site recombination strategy to achieve significant luminescence enhancement through topological engineering from non-emissive chiral metallomacrocycles (R/S-Au4) to highly circularly polarized luminescence (CPL) catenanes (R/S-Au8). The dynamical structural transformation of metallomacrocycles (R/S-Au4) to catenanes (R/S-Au8) was monitored by 1H and 31P NMR spectroscopy. Excited state dynamics and theoretical studies revealed that the increase of heavy atom effect in catenanes (R/S-Au8) effectively increases spin-orbit coupling constant from 4.03 (R-Au4) to 48.22 cm-1 (R-Au8), facilitating the intersystem crossing between S1 and T1. While R/S-Au4 with flexible metallocyclic structures tend to rapidly relax the excited states through thermally vibrational processes, interlocked structures of R/S-Au8 lead to better rigidity, thus effectively suppressing non-radiative deactivation and facilitating radiative T1→S0 relaxation, thus achieving highly efficient CPL with ca. 39% quantum yield in solution. Solution-processed circularly polarized organic light-emitting diodes (CP-OLEDs) based on R/S-Au8 attain high-efficiency deep-red circularly polarized electroluminescence (CPEL) peaked at 685 nm, with external quantum efficiency (EQE) of 9.9% and electroluminescence asymmetric factor of ± 2.2 × 10-3. In any case, this upgrading approach from discrete macrocycles to interlocked architectures opens a new avenue for developing high-performance emitting materials and devices.