Thermolysis of titanocene methyl compounds bearing t

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• 作者：Jiř ; &#xed ; Pinkas ; Ivana C&#xed ; sař ; ov&#xe1 ; Ana Conde ; Rosa F ; os ; Michal Hor&#xe1 ; č ; ek ; Jiř ; &#xed ; Kubiš ; ta ; Karel Mach
• 关键词：Titanium ; t-Butyltetramethylcyclopentadienyl ; Benzyltetramethylcyclopentadienyl ; Thermolysis ; Titanocene methyl ; Titanocene dimethyl
• 刊名：Journal of Organometallic Chemistry
• 出版年：2009
• 出版时间：1 June 2009
• 年：2009
• 卷：694
• 期：13
• 页码：1971-1980
• 全文大小：876 K

文摘

Elimination of methane during thermolysis of title compounds results in the formation of σ-Ti–C bond to t-butyl or benzyl group. The t-butyl-containing titanocene methyl compound [Ti(III)Me(η⁵-C₅Me₄t-Bu)₂] (5) eliminates methane at 110 °C to give cleanly [Ti(III)(η⁵:η¹-C₅Me₄CMe₂CH₂)(η⁵-C₅Me₄t-Bu)] (6). The methyl derivative of analogous benzyl-containing titanocene [Ti(III)Me(η⁵-C₅Me₄CH₂Ph)₂] was not isolated because it eliminated methane at ambient temperature to give [Ti(III)(η⁵:η¹-C₅Me₄CH₂-o-C₆H₄)(η⁵-C₅Me₄CH₂Ph)] (7) with one phenyl ring linked to titanium atom in ortho-position. The corresponding titanocene dimethyl compound [TiMe₂{η⁵-C₅Me₄t-Bu)}₂] (9) eliminates two methane molecules at 110 °C to give the singly tucked-in 1,1-dimethylethane-1,2-diyl-tethered titanocene [Ti{η⁵:η¹:η¹-C₅Me₃(CH₂)(CMe₂CH₂)}(η⁵-C₅Me₄t-Bu)] (11). In distinction, the analogous benzyl derivative [TiMe₂(η⁵-C₅Me₄CH₂Ph)₂] (10) eliminates at 110 °C only one methane molecule to afford [TiMe(η⁵:η¹-C₅Me₄CH₂-o-C₆H₄)(η⁵-C₅Me₄CH₂Ph)] (12) containing one phenyl group attached to titanium in o-position and one methyl group persisting on the titanium atom. This compound is stable at 150 °C for at least 3 h. The crystal structures of 5, 6, 7, and 10 were determined.