Novel Synthesis of Zirconocene Difluoride and Alkyl Monofluoride Complexes

Starting from zirconocene bis(trimethylsilyl)acetylene complexes Cp‘2Zr(L)(η2-btmsa) via
the 2-vinylpyridine complexes Cp‘2Zr(2-vipy) a novel synthetic method for zirconocene
difluoride and alkyl monofluoride complexes was elaborated. Examples with selected different
ligand systems Cp‘2 [Cp2 = bis(η5-cyclopentadienyl); ebthi = 1,2-ethylene-1,1‘-bis(η5-tetrahydroindenyl); (thi)2 = bis(η5-tetrahydroindenyl); Me2Si(η5-C5H4)2 = dimethylsilylbis(η5-cyclopentadienyl); (i)2 = bis(η5-indenyl); ebi = 1,2-ethylene-1,1‘-bis(η5-indenyl); and
Me2Si(η5-C9H10)2 = dimethylsilyl-1,1‘-bis(η5-tetrahydroindenyl)] were synthesized. In the
series of these investigations new complexes (i)2Zr(THF)(η2-btmsa) (1), rac-(ebi)Zr(THF)(η2-btmsa) (2), (thi)2Zr(2-vipy) (3), Me2Si(η5-C5H4)2Zr(2-vipy) (4), (i)2Zr(2-vipy) (5), and rac-(ebthi)Zr(2-Ph-vipy) (6) were prepared as starting materials. Different methods for preparation of
the zirconocene difluorides rac-(ebthi)ZrF2 (7), (thi)2ZrF2 (8), Me4C2(η5-C5H4)2ZrF2 (9), and
Me2Si(η5-C9H10)2ZrF2 (10) and the monofluorides Cp2Zr(F)(CH2CH2-2-Py) (11), rac-(ebthi)Zr(F)(CH2CH2-2-py) (12), (thi)2Zr(F)(CH2CH2-2-py) (13), Me2Si(η5-C5H4)2Zr(F)(CH2CH2-2-py)
(14), and Me2Si(η5-C9H10)2ZrF(Me) (15) are reported and compared. The molecular structures
of the bis-η5-tetrahydroindenyl complexes 3, 8, and 13 were confirmed by X-ray crystal
structure analysis.