Synthesis, Structural Characterization, and Reactivity of the (η²-Benzoato)iridium(III) Hydride Complex [mer-(Me₃P)₃Ir(η²-O₂CC₆H₅)(H)][PF₆]

mer-(Me₃P)₃Ir(H)(O₂CC₆H₅)(Cl) (1) reacts with T1[PF₆] to form the unusual (η²-benzoato)iridium(III) hydride complex [mer-(Me₃P)₃Ir(η²-O₂CC₆H₅)(H)][PF₆] (2). Compound 2 was crystallographically characterized and found to belong to the monoclinic space group P2₁/n with a = 6.899(2) Å, b = 11.783(3) Å, c = 32.303(8) Å, β = 92.89(2)°, and V = 2622.7(13) ų for Z = 4. The Ir-O(1) and Ir-O(2) distances are 2.244(8) and 2.198(8) Å, respectively. The coordinated oxygen-carbon distances are O(1)−C(7) = 1.294(15) Å and O(2)−C(7) = 1.284-(15) Å, respectively. Compound 2 reacts with dimethyl acetylenedicarboxylate (DMAD) to yield [mer-(Me₃P)₃-Ir{(MeOC(O)CC(H)(C(O)OMe)}(η²-O₂CC₆H₅)][PF₆] (3). Compound 3 crystallizes in the monoclinic space group P2₁/n with a = 13.129(4) Å, b= 17.837(8) Å, c = 16.939(4) Å, β = 109.81(2)°, and V = 3732(2) ų for Z = 4. The synthesis and reactivity of 2 are discussed with respect to the nature of the Ir-O linkage.