Excited-state properties and reactivity of [ReCL(CO) ₃ (2,2′-bipy)](2,2′-bipy = 2,2′-bipyridyl) studied by time-resolved infrared spectroscopy

Fast time-resolved infrared spectroscopy shows that the v(CO) bands of the important CO2-reducing complex, [ReCl(CO)3(2,2′-bipy)]1(2,2′-bipyridyl), shift up in frequency in the metal to ligand charge-transfer excited state and that the anion 1–, generated by reaction of the excited state with triethylamine, shows a lowering in frequency of the v(CO) bands significantly different from those of related but non-reducing complexes.