STRUCTURE AND REACTIVITY OF SUBSTITUTED DI-η5-CYCLOPENTADIENYL METAL DIHALIDES. CRYSTAL STRUCTURE OF DICHLOROBIS(Η5-t-BUTYLCYCLOPENTADIENYL)ZIRCONIUM(IV)

Article abstract of DOI:10.1016/0022-328X(86)80133-4

A new approach to the synthesis of t-butylcyclopentadienyl and related anions, via the addition of methyl- or other alkyl-lithium compounds to dimethylfulvene, is reported and details are given for the preparation of (η⁵-t-BuCp)2ZrCl2 and (η⁵-t-BuCp)2TiCl2.The zirconium compound is orthorhombic, P2₁2₁2, a 13.003(17), b 10.761(10), c 6.703(8) Angstroem.A crystal structure determination (R = 0.037, 980 reflections) shows that the t-butyl groups are directed away from each other on opposite sides of the molecule: this structure appears to be adopted only in molecules in which the substituent groups are too bulky to be accommodated directly above and below the MCl2 group.