Bis t-cyclopentadienyl dihydridozirconium

The method of preparation described here is an adaption of the original,5,6 which gives consistently high yields. 

In this reaction purified tetrahydrofuran (THF) is required, as well as a standardized solution of Li[AlH4] in tetrahydrofuran. The THF from freshly opened bottles is distilled from Li [A1H4]. ( Caution. Li[AlHJ is a hazardous material and must be handled in dry conditions and in small quantitites. Serious explosions can occur when impure THF is purified if it contains peroxides (see Reference 7). 

Simple apparatus for filtering under inert atmosphere. The flou of N2 or Ar is controlled by a finger over the base of the needle. 

ZrCl2(r/s-CsHs)2 + LiAlH(r-BuO)3 - ZrHCl(i7s-C5Hs)2 + LiCl + Al(r-BuO)3 Procedure  

The apparatus and procedures are similar to those in the preparation above and a 1L flask is used. A solution of lithium tri-ferf-butoxyhydridoaluminate 9 (28.6 g, 113 mmole) in purified THF (100 mL) is added slowly to a solution of ZrCl2(i7s-C5Hs)2 (32.9 g, 113 mmole) in THF (500 mL) with stirring. After complete addition, stirring is continued for 1 hour, after which the mono-hydrido complex is collected by anearobic filtration (Fig. 1) and washed with THF (yield 26.3 g, 90%). Anal. Calcd. for C10H ClZr ash (Zr02), 47.77% hydrolyzable H, 1.00 g-atom/mole Cl, 13.75. Found ash, 47.0% hydrolyzable H, 1.02 g-atom/mole Cl, 13.4. One-quarter mole of Li[AlH4] may be used instead of the tri-terr-butoxy hydrido complex, but the essential control of stoichiometry is more difficult (see Properties). 

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