Addition Reactions and Crystal Structure of trans-CH₃Ir(CO)(PPh₃)₂

The complex trans-MeIr(CO) (PPh₃)₂ readily undergoes addition reactions with a variety of small molecules such as H₂, CO, MeO₂CCH=CHCO₂Me, MeO₂CC=CCO₂Me, O₂, CH₃I, and H₂C(O) to yield well-characterized products. Further reactions of the addition complexes are noted in most cases. The species trans-MeIr(CO)(PPh₃)₂ crystallizes in the centrosymmetric triclinic space group P1 with a = 9.2497 (9) Å, b = 9.6080 (11) Å, c = 10.4855 (14) Å, α = 72.390 (10)°, β= 88.990 (9)°, γ= 69.224 (8)°, V = 826.22 (16) ų, Z = 1, and D(calcd) = 1.53 g cm^-3 for mol wt 759.9. Diffraction data (Mo Kα, 2θ-4.5-50.0°) were collected with a Syntex P2₁ automated four-circle diffractometer and refined to R_F = 1.8% and R_WF = 2.1% for the 2922 independent reflections (none rejected). The molecule lies on a center of symmetry and is disordered with CO and Me ligands occupying square-planar sites rigorously coplanar with the iridium atom. The Ir-p distances are each 2.300 (1) Å; estimated Ir—CO and Ir-Me distances are ~ 1.835 and ~2.17 Å, respectively.