Structural Aspects of Reversible Molecular Oxygen Uptake

Abstract
The system IrX(CO)[P(C6H5)3]2 in benzene solution adds mo lecular oxygen reversibly if X is chlorine and irreversibly if X is iodine. The crystal structure of the complex IrIO2(CO)[P(C6H5)3]2 • CH2Cl2 is reported here and compared with a previous study of the structure of IrClO2(CO)[P(C6H5)3]2. The O—O bond length is 1.47 ± 0.02 angstroms in the irreversibly oxygenated iodo-compound and 1.30 ± 0.03 angstroms in the reversibly oxygenated chloro compound.