Synthesis and Functionalization of Air-stable Luminescent Polychlorotriarylmethyl Radicals

Stable radicals possess open-shell electronic states and exhibit vivid physical properties such as electrical conductivity and magnetism attributed to unpaired electrons. Their luminescence properties, however, have yet to be well examined, mainly due to the rarity of emissive radicals and chemical reactivity in their excited states. I have developed highly-photostable luminescent organic radicals and luminescent open-shell metal complexes with luminescent radicals as ligands, and investigated photofunctions based on their doublet or multiplet states. The studies suggest that the radicals can demonstrate photofunctions unique to their open-shell electronic states, such as magnetic-field-controlled luminescence, which are unexpected or impossible to achieve for conventional closed-shell molecules. Such functions will expand the scope of the radicals in molecular photonics.