Reactivity of functionalised decamethyltitanocenes: Synthesis and structure of chiral monocyclopentadienyl titanium halogenides

The recently described unconventional substituted titanocene complex [Cp∗Ti{η5-C5Me3(CH2–CH(tBu)–η2-C2–CH(tBu)–CH2)}] (1) can be derivatised by simple means (Br2, HX with X = Cl, Br) to generate the titanocene dihalogenides 2-Br, 2-Cl, which give in a subsequent reaction besides Cp∗TiX3 (3-Br: X = Br, 3-Cl: X = Cl) the titanium complexes 4-Cl resp. 4-Br with one functionalised chiral cyclopentadienyl ligand. In the reaction of 1 with Et3N·3HF an analogous isostructural titanocene dihalogenide 2-F as well as the unusual dimeric anionic heptafluoride 5 are formed. All complexes have been characterised spectroscopically, and X-ray crystal structure determinations were performed for 4-Cl and 2-F.