Fig. 7 |. Proposed reaction mechanism and DFT calculations.

a, Computed Gibbs energy profiles for competing pathways for indene ring expansion from C-centred radical I• intermediate. Calculated Gibbs free energies (uB3LYP-D3/def2tzvpp//uB3LYP/def2svp–CPCM (acetonitrile)) are given in kcal mol−1. b, Energetics for the formation of intermediate• promoted by single electron transfer between the triplet [RuII] and reagent 2f. For computational details, see Supplementary Methods.