The Crystal and Molecular Structure of Nitrosylcarbonylbis(triphenylphosphine)iridium, Ir(NO)(CO)(P(C6H5)3)2

The structure of nitrosylcarbonylbis(triphenylphosphine)iridium, Ir(NO)(CO)(P(C6H5)3)2, has been determined from threedimensional X-ray data collected by counter methods. The compound crystallizes in the space group of the monoclinic system with four molecules in a unit cell of dimensions a = 11.271 (3) å, b - 18.036 (6) å, c = 18.240 (6) A, and β = 119.23 (2)°. The observed and calculated densities are 1.55 (±0,02) and 1.59 g cm-3, respectively, Least-squares refinement has led to a final value of the conventional R factor (on F) of 0.030 for the 2946 reflections having F2 > 3σ(F2). The structure consists of well-separated molecules, and the coordination around the iridium atom is distorted tetrahedral. Structural parameters describing this geometry are the P-Ir-P angle of 103.9 (1)°, the N-Ir-C angle of 128.8 (2)°, and the dihedral angle between the P-Ir-P and N-Ir-C planes of 84.3 (2)°. The nitrosyl ligand is coordinated to the metal in a nearly linear fashion, with an Ir-N bond length of 1.787 (8) A and an Ir-N-0 bond angle of 174.1 (7)°. The compound is therefore formulated as an NO+ complex of iridium(-I). Other important bond distances in the molecule are as follows (å): Ir-P, 2.323 (2), 2.324 (2); Ir-C, 1.873 (11); C-O, 1.144 (11); and N-O, 1.180 (9).