Multiple Insertion of Unsaturated Molecules into the Zr−N Bonds of [<i>η</i>⁵:<i>σ</i>-Me₂A(C₉H₆)(C₂B₁₀H₁₀)]Zr(NMe₂)₂ (A = C, Si)

Abstract

The compounds [η5:σ-Me2A(C9H6)(C2B10H10)]Zr(NMe2)2 (A = C, Si) reacted with CS2, PhCN, CH2CHCN, nBuNCS, and PhNCO to give the mono-, di-, and triinsertion products, depending upon the substrates. These unsaturated substances inserted exclusively into the Zr−N bonds, and the Zr−C(cage) bond remains intact in all reactions. It is believed that the preference of Zr−N over Zr−C(cage) insertion is governed by steric factors. The metal amide compounds also initiated the polymerization of CH2CHCN to produce poly(acrylonitrile) and catalyzed the trimerization of PhNCO. On the other hand, they reacted with methyl methacrylate to afford [{η5:σ-Me2A(C9H6)(C2B10H10)}Zr(OCH3)(μ-OCH3)]2 and CH2C(Me)CONMe2. All insertion products were fully characterized by various spectroscopic data, elemental analyses, and X-ray diffraction studies.