Photoactivatable europium luminescence turn-on by photo-oxygenation of β-diketone having pyrrole rings

This work demonstrates a novel photoactivatable turn-on-type lanthanide(III) luminescence. A beta-diketone substrate having redox-active pyrrole moieties (LH2) undergoes efficient photo-oxygenation to afford the corresponding alpha-alkoxy diketone (LHOH) in the presence of lanthanide(III) ions, which trigger bright europium(III) red luminescence (PA-Eu-III) turn-on, as well as activating the near-infrared luminescence (lambda(em) = 976 nm) of ytterbium(III). A photo-patterning process for security imaging is successfully demonstrated.