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

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.