Key points are not available for this paper at this time.
Selective low energy excitation of the metal-to-ligand charge transfer (MLCT) transition in Ru(dmb)(3)(2+)(dmb = 4,4'-dimethyl-2,2'-bipyridine) in the presence of anthracene or 9,10-diphenylanthracene yields easily visualized upconverted singlet fluorescence resulting from triplet-triplet annihilation at low excitation power.
Islangulov et al. (Sat,) studied this question.