The dissociation of the central N-donor is the major transformation within the CN(Me)P ligand upon the activation and the hydride complex with dissociated was observed in minor amounts (3% NMR yield) (see Figure S11). The difference between Mn hydrides with dissociated N or P donor is reflected in the hydride ligand shifts in the and supported by DFT calculations (Table ). Based on DFT analysis we assume that complex 8 might exist as an octahedral complex with facially bound P and C donor groups with isomers distinguished by hydride ligand placement trans to either NHC, phosphine or carbonyl ligand (8a, 8b and 8c respectively, Figure ); all three featuring the dissociated central N donor group. for full spectra) and IR spectra (c) of complex Mn-7 (black) and in-situ generated complex 8 (red) recorded in THF. Time-dependent IR spectra evolution (d) for the reaction of complex 8 with olefin (0 to 49 min, grey to black). Molecular structure (e) of complex Mn-7 in the solid state with thermal ellipsoids drawn at 50% probability.