Crystal structure of di-n-butylbis(η5-pentamethylcyclopentadienyl)hafnium(IV)

The crystal structure of the title compound, [Hf(C10H15)2(C4H9)2], reveals two independent molecules in the asymmetric unit. The diffraction experiment was performed with a racemically twinned crystal showing a 0.529 (5):0.471 (5) component ratio. Each HfIV atom is coordinated by two pentamethylcyclopentadienyl and two n-butyl ligands in a distorted tetrahedral geometry, with the cyclopentadienyl rings inclined to one another by 45.11 (15) and 45.37 (16)°. In contrast to the isostructural di(n-butyl)bis(η5-pentamethylcyclopentadienyl)zirconium(IV) complex with a noticeable difference in the Zr–butyl bonding, the Hf—Cbutyl bond lengths differ from each other by no more than 0.039 (3) Å