Metallaborane chemistry. Part III. Oxidative-insertion reactions of eleven-atom monocarbon carbaborane species with zerovalent nickel, palladium, and platinum complexes; the molecular and crystal structure of 1,1 -bis(t-butyl isocyanide)-2-(trimethylamine)-2-carba-1-pallada-closo-decaborane(10)

Abstract

Reaction of [Ni(cod)(Bu^tNC)₂], [Pd(Bu^tNC)₂], and [Pt(trans-stilbene)(PEt₃)₂] with [Me₄N]⁺[closo-CB₁₀H₁₁]^–and closo-2-NMe₃-2-CB₁₀H₁₀ affords the closo-metallacarbaboranes [Me₄N]⁺[1,1-L₂-1,2-MCB_l0H₁₁]^– and [1,1-L₂-2-NMe₃-1,2-MCB_l0H_l0](M = Ni or Pd, L = Bu^tNC; M = Pt, L = PEt₃). The molecular structure of the palladium complex has been determined from a single-crystal X-ray diffraction study and refined to R= 0.042 for 3 319 independent observed reflections. Crystals are monoclinic, space group P2₁/n. with cell dimensions of a= 10.947(3), b= 15.194(4), c= 15.804(4)Å, β= 103.45(2)°. The 12-atom polyhedron has a very distorted icosahedral geometry, marked by an extremely weak metal-carbon interaction with Pd–C(cage) at 2.600(6)Å. The metal to carbaborane bonding is described in terms of approximately square planar co-ordination.