Exploration of Uncharted 3PES Territory for [Ru(bpy)3]2+: A New 3MC Minimum Prone to Ligand Loss Photochemistry

We have identified a new 3 MC state bearing two elongated Ru-N bonds to the same ligand in [Ru(bpy) 3 ] 2+ . This DFT-optimized structure is a local minimum on the 3 PES. This distal MC state ( 3 MC cis ) is destabilized by less than 2 kcal/mol with respect to the classical MC state ( 3 MC rans ), and energy barriers to populate 3 MC cis and 3 MC rans from the 3 MLCT state are similar according to nudged elastic band minimum energy path calculations. Distortions in the classical 3 MC rans , that is, elongation of two Ru-N bonds toward two different bpy ligands, are not expected to favor the formation of ligand-loss photoproducts. On the contrary, the new 3 MC cis could be particularly relevant in the photodegradation of Ru(II) polypyridine complexes.