Superstructural Assembly of Ag₂₄ Nanoclusters with Different Ligands Exhibiting Mechanoresponsive Luminescence

While single thiolate-stabilized silver nanoclusters (NCs) are well studied, multiligand-protected analogues remain rare. Herein, we report a luminescent Ag₂₄ nanocluster, co-stabilized by two distinct heterocyclic thiols, 2-mercapto-5-n-propylpyrimidine and 6-(dibutylamino)-1,3,5-triazine-2,4-dithiol, together with triphenylphosphine, whose composition was confirmed by high resolution electrospray ionization (HR-ESI) mass spectrometry. It shows aggregation-caused quenching as it self-assembles into nonemissive sheets, but the emission reappears after mechanical grinding, demonstrating mechanoresponsive luminescence. Interestingly, individual ligands form nonluminescent clusters exhibiting no aggregation behavior. Femtosecond transient absorption measurements indicate that aggregation alters the excited-state dynamics, reflecting the effect of multiligand stabilization on structural rigidity and photophysical behavior in the NCs.