Insertion of isocyanides into zirconium-alkyl bonds of di-ansa-zirconocene complexes. X-ray molecular structure of [Zr{(SiMe2)(2)(eta(5)-C5H3)(2)}Cl{eta(2)-C(i-Pr)N(2,6-Me2C6H3)}]

New dicyclopentadienyl iminoacyl zirconium complexes have been prepared and characterized by NMR spectroscopy. The reaction of [Zr{(SiMe2)(2)(eta(5)-C5H3)(2)}Me-2] with CNR (R = 2,6-Me2C6H3, t-Bu) yields [Zr{(SiMe2)(2)(eta(5)-C5H3)(2)}Me(eta(2)-CMeNR)] (R = 2,6-Me2C6H3, t-Bu), which reacts with a stoichiometric amount of water to give the mu-oxo dimers [Zr{(SiMe2)(2)(eta(5)-C5H3)(2)}(eta(2)-CMeNR)](2)(mu-O) (R = 2,6-Me2C6H3, t-Bu). The chloro neophyl complex [Zr{(SiMe2)(2)(eta(5)-C5H3)(2)}Cl(CH2CMe2Ph)] and other beta-hydrogen containing zirconium chloro alkyls [Zr{(SiMe2)(2)(eta(5)-C5H3)(2)}ClR] (R = Et, n-Pr, i-Pr) react with CN(2,6-Me2C6H3) to yield the related chloro iminoacyl complexes [Zr{(SiMe2)(2)(eta(5)-C5H3)(2)}Cl{eta(2)-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 H-1 and C-13 NMR spectroscopy and the X-ray molecular structure of [Zr{(SiMe2)(2)(eta(5)-C5H3)(2)}Cl{eta(2)-C(i-Pr)N(2,6-Me2C6H3)}] was studied by diffraction methods to prove the expected 'inside' coordination of the iminoacyl nitrogen atom. (C) 1997 Elsevier Science S.A.