Irradiation for improving Violet-Blue Light Contribution of tri- and Polychromatic Polysulfone Host-guest systems

Herein, we explored the effect of light irradiation on polysulfone films dopped with highly emissive guests. We report irradiation promoted interactions in a polysulfone membrane functionalized with a fluorinated β-diketone species leading to an improved Violet-Blue Light Contribution in Polychromatic Polysulfone Host-Guest Systems. We suggest that irradiation at higher UV wavelengths, leads to an amorphous-to-monomer phase transformation of the fluorinated boron guest, BF₂dbm (dbm as dibenzoylmethanoate), to which corresponds conversion of part of the green emission from aggregates to cyan-blue fluorescence, characteristic of the monomeric form. Also, irradiation at lower wavelength promotes host-guest BF₂dbm@PSU strong interaction giving rise to increased emission in the violet-blue region by sacrificing the contribution from the intense blue-cyan emission from BF₂dbm molecules. In the current work we also prepared combinations of Tb³⁺ and Eu³⁺ highly fluorinated complexes and evaluated its tuneable emission due to light driven ligand interaction with host matrix. The judicious choice of molecular ratio between Tb³⁺ and Eu³⁺ complexes allow rationally designed preparation of triple-emissive flexible films when irradiated at 300, 320 and 330 nm, to be used in highly advanced anti-counterfeiting technologies. In short, we propose a simple and new powerful approach for emission colour tuning of polysulfone dopped films.