In summary, amidinate precursors, such as Ir(COD)(DIA) (1-Ir), react with molecular silanols, yielding Ir-TBOS. This result is consistent with a grafting mechanism that involves the protonation of the aminidate ligand that remains bound to Ir. Most striking is the finding that the reaction of 1-Ir and O-H groups is reversible for both molecular and surface species. While fully reversible for the molecular species, the de-grafting is only partial (ca. 50%) for the surface species, further corroborating the