The Excited‐State Creutz–Taube Ion
German E. Pieslinger, Ivana Ramírez‐Wierzbicki, Alejandro Cadranel
Abstract
Abstract The excited‐state version of the Creutz–Taube ion was prepared via visible light excitation of [(NH 3 ) 5 Ru II ( μ ‐pz)Ru II (NH 3 ) 5 ] 4+ . The resulting excited state is a mixed valence {Ru III–δ ( μ ‐pz⋅ − )Ru II+δ } transient species, which was characterized using femtosecond transient absorption spectroscopy with vis‐NIR detection. Very intense photoinduced intervalence charge transfers were observed at 7500 cm −1 , revealing an excited‐state electronic coupling element H DA =3750 cm −1 . DFT calculations confirm a strongly delocalized excited state. A notable consequence of strong electron delocalization is the nanosecond excited state lifetime, which was exploited in a proof‐of‐concept intermolecular electron transfer. The excited‐state Creutz–Taube ion is established as a reference, and demonstrates that electron delocalization in the excited state can be leveraged for artificial photosynthesis or other photocatalytic schemes based on electron transfer chemistry.