Insertion of isocyanides into zirconium-alkyl bonds of di-ansa-zirconocene complexes. X-ray molecular structure of [Zr{(SiMe2)2(η5-C5H3))Cl(η2-C(i-Pr)N(2,6-Me2C6H3)}]

Abstract

New dicyclopentadienyl iminoacyl zirconium complexes have been prepared and characterized by NMR spectroscopy. The reaction of [Zr{SiMe2)2(η5-C5H3)2)Me2] with CNR (R  2,6-Me2C6H3, t-Bu) yields [Zr((SiMe2)2(η5-C5H3)2Me(η2-CMeNR)] (R = 2,6-Me2C6H3, t-Bu), which reacts with a stoichiometric amount of water to give the μ-oxo dimers [Zr{(SiMe2)2(η5-C5H3)2}(η2-CMeNR)]2(μ-O) (R = 2,6-Me2C6H3, t-Bu). The chloro neophyl complex [Zr{(SiMe2)2(η5-C5H3)2}Cl(CH2CMe2Ph)] and other β-hydrogen containing zirconium chloro alkyls [Zr{(SiMe2)2(η5-C5H3)2}CIR] (R  Et, n-Pr, i-Pr)_ with CN(2,6-Me2C6H3) to yield the related chloro iminoacyl complexes [Zr{(SiMe2)2(η5-C5H3)2)Cl}η2-CRN(2,6-Me2C6H3)}] (R  Et, n-Pr, i-Pr), whereas no reaction was observed when CN(t-Bu) was used. All the new iminoacyl complexes were characterized by 1H and 13C NMR spectroscopy and the X-ray molecular structure of [Zr{(SiMe2)2(η5-C5H3)2)Cl{η2-C(i-Pr)N(2,6-Me2C6H3)}] studied by diffraction methods to prove the expected ‘inside’ coordination of the iminoacyl nitrogen atom.