Environment-responsive Pt(II) complexes boost aggregation-enhanced emission and singlet oxygen production

Abstract

Here, we introduce an environment-tuning strategy to simultaneously boost aggregation-enhanced emission (AEE) and singlet oxygen (1O2) generation in PEGylated platinum(II) pyridyl complexes. Different amphiphilic Pt(II) species bearing triazole/tetrazole NˆNˆN ligands self-assemble in response to solvent polarity, polymer confinement, and packing forces, enabling precise control over intermolecular Pt···Pt and π···π interactions. This aggregation control strengthens the triplet-state population, delivering parallel gains in luminescence and photosensitization without modifying the core chromophore. Emission quantum yields rise from dilute-solution values to 25% in aggregated states and 0.25% in polymethyl methacrylate (PMMA) films, while 1O2 quantum yields reach ∼60% in aggregates and 49% in polystyrene (PS) films. This simple, modular approach couples emission enhancement with photoreactive oxygen production, offering a powerful design platform for multifunctional materials in photodynamic therapy, photocatalysis, and optical sensing.