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 β-diketone substrate having redox-active pyrrole moieties (LH2) undergoes efficient photo-oxygenation to afford the corresponding α-alkoxy diketone (LHOH) in the presence of lanthanide(iii) ions, which trigger bright europium(iii) red luminescence (PA-EuIII) turn-on, as well as activating the near-infrared luminescence (λem = 976 nm) of ytterbium(iii). A photo-patterning process for security imaging is successfully demonstrated.