INSERTION OF ISOCYANIDES INTO ZIRCONIUM-ALKYL BONDS OF DI-ANSA-ZIRCONOCENE COMPLEXES - X-RAY MOLECULAR-STRUCTURE OF (ETA(5)-C5H3)(2))CL(ETA(2)-C(I-PR)N(2,6-ME2C6H3))]

New dicyclopentadienyl iminoacyl zirconium complexes have been prepare d 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{(S iMe2)(2)(eta(5)-C5H3)(2)}Me(eta(2)-CMeNR)] (R = 2,6-Me2C6H3, t-Bu), wh ich reacts with a stoichiometric amount of water to give the mu-oxo di mers SiMe2)(2)(eta(5)-C5H3)(2)}(eta(2)-CMeNR)](2)(mu-O) (R = 2,6-Me2C6 H3, t-Bu). The chloro neophyl complex [Zr{(SiMe2)(2)(eta(5)-C5H3)(2)}C l(CH2CMe2Ph)] and other beta-hydrogen containing zirconium chloro alky ls [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 2)(2) (eta(5)-C5H3)(2)}Cl{eta(2)-CRN(2,6-Me2C6H3)}] (R = Et, n-Pr, i-Pr), wh ereas no reaction was observed when CN(t-Bu) was used. All the new imi noacyl complexes were characterized by H-1 and C-13 NMR spectroscopy a nd the X-ray molecular structure of (eta(5)-C5H3)(2)}Cl{eta(2)-C(i-Pr) N(2,6-Me2C6H3)}] was studied by diffraction methods to prove the expec ted 'inside' coordination of the iminoacyl nitrogen atom. (C) 1997 Els evier Science S.A.