Elimination process from the [(diphenylphosphino)methyl]zirconium hydride [Cp2ZrH(CH2PPh2)]n

Article abstract of DOI:10.1021/om00043a027

The synthesis of [Cp₂ZrH(CH₂PPh₂)]_n, 1, and its chemical behavior toward different organic or organometallic substrates are described. The chemical reduction of the hydride 1 produced a paramagnetic Zr(III) species formulated as [CpZr(η²-CH₂PPh₂)₂], and a redistribution reaction from the unstable [Cp₂ZrH(CH₂PPh₂)]^- is suggested. The thermolytic experiment of 1 led to the Zr(III) species Cp₂ZrH and [Cp₂Zn(η²-CH₂PPh₂)], and a mechanistic pathway implying the reductive elimination of the phosphine CH₃PPh₂ is proposed. Indirect evidence comes from the thermolysis of [Cp₂ZrD(CH₂PPh₂)]_n and [(C₅D₅)₂ZrD(CH₂PPh ₂)]_n or from the reactivity of 1 with PhC≡CPh, Cp₂Zr(Ph)₂, or Cp₂Zr(η⁴-butadiene). A Zr(IV)-Zr(II) homodimetallic hydride [Cp₂Zr(μ-H)(μ-CH₂PPh₂)ZrCp₂] is postulated as an intermediate in the decomposition scheme of 1.