Oxygen-Carrying Iridium Complexes: Kinetics, Mechanism, and Thermodynamics

The rates of oxygenation and deoxygenation of a series of iridium complexes increase and decrease, respectively, with increasing electron-releasing tendency of the anionic ligands (A) attached to the metal atom in the oxygen-carrying compounds, [IrA(CO)(Ph$_{3}$P)$_{2}$]. Calculated heats of oxygenation (-ΔH$_{2}{}^{0}$), related to Ir-O$_{2}$ bond energies, are proportional to the previously reported O-O bond lengths in the oxygen adducts, [O$_{2}$IrA(CO)(Ph$_{3}$P)$_{2}$].