Solution and Solid-State Emission Toggling of a Photochromic Hydrazone

The proliferation of light-activated
switches in recent years has
enabled their use in a broad range of applications encompassing an
array of research fields and disciplines. All current systems, however,
have limitations (e.g., from complicated synthesis to incompatibility
in biologically relevant media and lack of switching in the solid-state)
that can stifle their real-life application. Here we report on a system
that packs most, if not all, the desired, targeted and sought-after
traits from photochromic compounds (bistability, switching in various
media ranging from serum to solid-state, while exhibiting ON/OFF fluorescence
emission switching, and two-photon assisted near-infrared light toggling)
in an easily accessible structure.