Activation of a vinyl carbon–hydrogen bond in a tris(pyrazolyl)boratoiridium complex. The X-ray crystal structure of [IrH{HB(pz)3}(σ-C8H13)(η2-C8H14)]

Abstract

Reaction between [(Ir(µ-Cl)(C₈H₁₄)₂}₂](C₈H₁₄= cyclo-octene) and Na[ HB(pz)](pz = pyrazolyl) affords the vinyl hydrido complex [IrH{HB(pz)₃}(σ-C₈H₁₃)(η²-C₈H₁₄)]. Protonation of this complex gives [IrH{HB(pz)₃}(η²-C₈H₁₄)₂]BF₄. Treatment of [IrCl(C₂H₄)₄] with Na[HB(pz)₃] yields [Ir{HB(pz)₃)(η²-C₂H₄)₂]. The molecular structure of [IrH{HB(pz)₃}(σ-C₈H₁₃)(η²-C₈H₁₄)](1) has been determined by X-ray analysis. Crystals of (1) are monoclinic, space group P2₁/_n, with a= 20.284(2), b= 12.265(1), c= 20.554(2)Å, β= 97.103(7)°, and Z= 8. The co-ordination around the iridium atom is distorted octahedral involving the three N atoms from the tris(pyrazolyl) borato on one side, and a hydride, a π-bonded cycle-octene, and a π-bonded cyclo-octenyl group on the other; the last three ligands are mutually cis.