SYNTHESIS, CHARACTERIZATION, CRYSTAL STRUCTURE AND CARBONYLATION OF THE PERFLUOROPHENOXYIRIDIUM(I) COMPLEX, trans-(C6F5O)Ir(CO)(PPh3)2

Article abstract of DOI:10.1016/S0022-328X(00)99735-3

trans-(C6F5O)Ir(CO)(PPh3)2 is readily prepared by reaction of NaOC6F5 with trans-Ir(CO)(PPh3)2Cl.Reaction of trans-(C6F5O)Ir(CO)(PPh3)2 with CO does not lead to carbonylation of the Ir-O bond, consistent with expectations of OC6F5(1-) loss from the coordination sphere.To further define the bonding of OC6F5(1-) to the iridium we have determined the structure. trans-(C6F5O)Ir(CO)(PPh3)2 crystallizes in the centrosymmetric triclinic space group P1(C¹_i; No. 2) with a 11.901(3), b 12.823(4), c 14.153(5) Angstroem, α 74.223(24), β 88.044(25), γ 66.267(23) deg, V 1895.8(10) Angstroem³ and Z =2.Diffraction data (Mo-K_α, 2θ 4.5-50.0 deg) were collected with a Syntex P2₁ automated four-circle diffractometer and the structure was refined to R_F 4.0percent for all 6727 independent data (R_F 3.3percent for those 5870 data with F₀ > 6?(F₀)).The d⁸ iridium(I) atom has the expected square-planar coordination geometry with Ir-P 2.320(1) and 2.321(1) Angstroem, Ir-CO 1.798(6) Angstroem and Ir-OC6F5 2.058(3) Angstroem.Molecular dimensions are very similar to those of trans-PhOIr(CO)(PPh3)2 except for the Ir-O-C6F5 angle of 135.4(3) deg, a value 8.9 +/- 0.4 deg greater than the Ir-O-C6H5 angle of 126.5(3) deg.This is interpreted as due to increased donation of p-electron density from oxigen to the electronegative C6F5 (vis a vis C6H5) group.