NaYF4:Yb(3+)/Er(3+)nanocrystals upconvert near infrared light (980 nm) into higher energy visible photons capable of effecting the photodissociation of the monodentate pyridyl ligand in cis-[Ru(bpy)2(py)2]Cl2: opening an opportunity for advancing the use of photoactivatable metal complexes in medicine and biology.