Novel dinuclear dimethylamido-3,5-dimethylpyrazolato and tetranuclear dimethylamido-3,5-dimethylpyrazolato-polyoxo zirconium(iv) complexes. Synthesis and structural characterisation

Abstract

The dinuclear dimethylamido-tris(3,5-dimethylpyrazolato)-zirconium(IV) complex [Zr(3,5-Me₂Pz)₃(NMe₂)]₂1 is prepared by treatment of [Zr(NMe₂)₄] with 3 equivalents of 3,5-dimethylpyrazole (3,5-Me₂PzH) with elimination of dimethylamine. When [Zr(NMe₂)₄] reacted with 2 equivalents of 3,5-Me₂PzH, the bis(dimethylamido)-bis(3,5-dimethylpyrazolato)zirconium(IV) compound [Zr(3,5-Me₂Pz)₂(NMe₂)₂]₂2 is obtained. Hydrolysis of [Zr(3,5-Me₂Pz)₃(NMe₂)]₂ in wet toluene affords the tetranuclear oxo compound [Zr₄(η²-3,5-Me₂Pz)₄(NMe₂)₂(μ₃-O)₂(μ₂-3,5-Me₂Pz)₄(μ₂-NMe₂)₂] 4. All synthesised compounds are characterised by NMR spectroscopic and analytical methods. Single crystal X-ray diffraction analysis has established the molecular structures of 1 and 4.