Reaction of cyclopentadienyl zirconium derivatives with sterically encumbered arylaluminum hydrides: X-ray crystal structure of (η 5-C 5H 5) 2(H)Zr( μ2-H) 2Al(H)C 6H 2-2,4,6-Bu t3

Abstract

The novel reactions between Cp 2ZrMe 2 (Cp=η 5-C 5H 5) and (Mes*AlH) 2 (Mes*=C 6H 2-2,4,6-Bu t 3) to afford Cp 2(H)Zr(μ 2-H) 2Al(Me)Mes* ( 1) and between Cp 2Zr(Cl)H and [Mes*AlH 3Li(THF) 2] 2 to give Cp 2(H)Zr(μ 2-H) 2Al(H)Mes* ( 2) are described. The X-ray crystal structure and NMR spectroscopy of 1 indicate that, in the crystalline product, a methyl group has been transferred from zirconium to aluminum, and the metals have been connected by two hydrogen bridges. The compounds Cp 2ZrH 2 and Mes*AlMe 2 were also obtained as reaction products in the synthesis of 1. The aluminum center is four-coordinate in contrast to the five- or six-coordination observed in previously published complexes. Compound 2, which is believed to have a very similar structure to that of 1, was obtained in moderate yield as a colorless crystalline material.