Organic radicals have gained some attention lately for their photoluminescence, but examples of emission from organic radical-containing compounds are scarce due to rapid excited state quenching. Nevertheless, upon excitation either in the UV or visible, 1-Yb displayed characteristic NIR emission from Yb 3+ (max = 975 nm, Figure ). Interestingly, the emission intensity was broadly proportional to molar extinction co-efficient at each of the wavelengths used, despite assignment of the absorptions in the visible region to excitation of pd •-, which is coordinated to Yb 3+ via the radical semiquinone O,Oʹ binding site. Excitation of 1-Dy, meanwhile, resulted in negligible emission from Dy 3+ , which was only observed upon irradiation with UV light (ESI Figure ). Presumably, there is no efficient ET pathway due to the similarity in excited state energies between pd •-and Dy 3+ .