The preparation and crystal structure of the dioxygen adduct of bis(diphenylethylphosphine)chlorocarbonyl iridium(I)

Abstract

The synthesis of the titled compound has been accomplished, its infrared vibrational spectra measured and the crystal structure determined. The OO, CO, and IrCl stretching frequencies were found to be 848, 1997 and 293 cm −1, respectively. The OO distance was found from the crystal structure analysis to be 1.469(10) Å. These data are in agreement with quadrupole resonance data that indicate this compound and those closely related must be viewed as peroxo-metal species and not molecular oxygen bound to metal. The crystal structure consists of isolated O 2IrCOCl[P(C 6H 5) 2C 2H 5] 2 molecules separated by ordinary van der Waals distances. The molecule is most simply described as a trigonal bipyramid with the O 2-center, CO and Cl moieties defining the equatorial plane. As expected the O 2 2− is bound to the Ir side on. The metaloxygen(2), metalphosphorous(2), metalchlorine and metalcarbon distances are: 2.033(7), 2.083(7), 2.363(3), 2.363(3), 2.356(3) and 1.900(12) Å, respectively. The O distance is 1.469(10) Å. Crystallographic Data: Monoclinic P2 1/a; a = 14.772(2), b = 19.604(4), c = 9.929(1) Å and β = 101.02(4)°; Z = 4; D obs = D calc = 1.67 gcm −3; 3306 non-zero hkl reflections were corrected for absorption and decay and used to solve and refine the structure by full matrix least-squares to a final R of 0.0431.