The structure of dichloronitrosylbis(triphenylphosphine)iridium, IrCl2(NO)(P(C6H5)3)2, has been determined from three-dimensional X-ray data collected by counter methods. The compound crystallizes in the space group C2h6-I2/a of the monoclinic system with four molecules in a unit cell of dimensions a = 15.851 (4), b = 9.624 (3), c = 22.050 (6) Å, β = 104.6 (3)°. The observed and calculated densities are 1.66 (± 0.02) and 1.67 g/cm3. Least-squares refinement of the structure has led to a final value of the conventional R factor (on F) of 0.032 for the 1338 reflections having F2 > 3σ(F2). The structure consists of well-separated discrete molecules. There is a crystallographicaliy imposed twofold axis on the molecule and the geometry around the iridium atom is approximately square-pyramidal with the nitrogen atom of the nitrosyl group occupying the apical position. Despite the fact that the oxygen and nitrogen atoms are disordered about the twofold axis an iridium-nitrogen-oxygen bond angle of 123 (2)9 may be derived from the data. Important bond lengths in the molecule are as follows: Ir-Cl, 2.348 (2); Ir-P, 2.367 (2); Ir-N, 1.94 (2); N-O, 1.03 (2) Å. This complex provides another example of the nitrosyl ligand coordinated to iridium in a nonlinear fashion. The bonding in this complex is rationalized in terms of a qualitative molecular orbital scheme, and the complex is described formally as an NO- complex of iridium(III).
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Inorganic Chemistry