Reactions of Ir(CO)(H)(P(p-tolyl)₃)₃ with SO₂ and O₂ Mixtures and with H₂SO₄, Formation of a Sulfate-Bridged Dimer, and Crystal and Molecular Structure of Ir(CO)(H)(SO₂)(P(p-tolyl)₃)₂

Reactions of HIr(CO)(P(p-tolyl)₃)₃ with SO₂, O₂, mixtures of SO₂ and O₂, and H₂SO₄ are described. Reactions with mixtures of SO₂/O₂. and with H₂SO₄ lead to a common product, Ir₂H₄(μ-SO₄)(P(p-tolyl)₃) ₆, where a bidentate SO₄^2- bridges the iridium centers. The complex HIr(CO)(P(p-tolyl)₃)₃ is stable toward O₂ but reacts readily with SO₂ to give HIr(CO)(SO₂)(P(p-tolyl)₃)₂, which was characterized by a crystal structure determination. The species Ir(CO)(H)(SO₂)(P(p-tolyl)₃)₂ crystallizes in the centrosymmetric triclinic space group P1̄ with a = 10.675(1) Å, b = 10.882(1) Å, c = 17.740(2) Å, α = 84.626(10)°, β= 83.432(10)°, γ = 87.043(10)°, V = 2036.6(3) ų, and Z =2. Diffraction data (Mo Kα, 20 = 4.5-45.0°) were collected on a Siemens R3m/V diffractometer, and the structure was refined to R = 3.00% for 4218 independent reflections with F_o > 6σ(F_o). The five-coordinate iridium(I) center has a distorted environment (closer to trigonal bipyramidal than to square pyramidal) with H(1)-Ir(1)-S(1) = 171.4(23)°. Bond lengths are Ir-P = 2.303(2) and 2.320(2) Å, Ir-SO₂ = 2.372(2) Å, Ir-CO = 1.906(8) Å, and Ir-H= 1.65(7) Å. The SO₂ ligand has bond distances of S(1)-O(1) = 1.442(7) and S(1)-O(2) = 1.441(7) Å, with O(1)-S(1)-O(2) = 113.1(4)°.