Activation of the (Trimethylsilyl)tetramethylcyclopentadienyl Ligand in Zirconocene Complexes

0181606 - UFCH-W 20030034 RIV US eng J - Článek v odborném periodiku
Horáček, Michal - Štěpnička, P. - Kubišta, Jiří - Fejfarová, K. - Gyepes, R. - Mach, Karel
Activation of the (Trimethylsilyl)tetramethylcyclopentadienyl Ligand in Zirconocene Complexes.
Organometallics. Roč. 22, - (2003), s. 861-869. ISSN 0276-7333. E-ISSN 1520-6041
Grant CEP: GA ČR GA203/00/D037; GA ČR GA203/02/0436
Výzkumný záměr: CEZ:AV0Z4040901
Klíčová slova: trimethylsilyl * zirconocene complexes
Kód oboru RIV: CF - Fyzikální chemie a teoretická chemie
Impakt faktor: 3.375, rok: 2003

Reduction of [ZrCl2{.eta.5-C5Me4(SiMe3)}2] (1) with excess magnesium in tetrahydrofuran affords a mixture of monomeric zirconocene hydride [ZrH{.eta.1:.eta.5-C5Me4(SiMe2CH2)}{.eta.5-C5Me4(SiMe3)}] (2) and dimeric, tetranuclear Zr(III)- and Zr(IV)-magnesium hydride complexes 3 and 4, respectively. In the presence of bis(trimethylsilyl)ethyne (btmse), a similar reduction yields the .eta.2-alkyne complex [Zr{.eta.5-C5Me4(SiMe3)}2(.eta.2-btmse)] (5) as the major product and compounds 2-4 as minor impurities. Upon thermolysis in vacuum, 5 undergoes a two-fold hydrogen transfer from trimethylsilyl groups in the zirconocene intermediate to leaving btmse to afford [Zr{.eta.5:.eta.1-C5Me4(SiMe2CH2)}2] (6) and a mixture of alkenes (E)- and (Z)-Me3SiCH=CHSiMe3 (E » Z). Crystal structures of compounds 2, 4, 5, and 6 were determined by X-ray crystallography.
Trvalý link: http://hdl.handle.net/11104/0078147