692779-27-4Relevant academic research and scientific papers
Models of intermediates in metallocene-catalyzed alkene polymerizations: Observation of a d0 cationic titanium-alkyl-alkene complex and decomposition by β-allyl elimination
Carpenetti II, Donald W.
, p. 1287 - 1290 (2008/10/08)
Low temperature activation of Cp2*Ti[η1, η1- CH2CH(CH2CH=CH2)CH 2] (3) with [HN(CH3)(C6H5) 2] [B(C6F5)4] led to the formation of Cp2*Ti[η1,η2 -CH 2CH(CH3)CH2CH=CH2][B(C 6F5)4] (6) as determined by 1H NMR spectroscopy. Cp2*Ti[η1,η 2-CH2CH(CH3)CH2CH=CH 2][B(C6F5)4] undergoes rapid quantitative β-allyl elimination at temperatures as low as -140 °C. The resulting cationic titanium allyl complex [Cp2*Ti(η 3-CH2CHCH2)][B(C6F5) 4] (4) exhibits a static structure at low temperatures, but interconversion of η3-η1 binding modes can be observed at higher temperatures. Lineshape analysis of this process yielded Δ?-10 °C) = 13.7 ± 0.6 kcal mol-1, ΔH? = 9.8 ± 0.6 kcal mol-1, and ΔS? = -15 ± 3 eu. The use of neutral borane B(C6F 5)3 also resulted in [β-allyl elimination with the formation of [Cp2*Ti(η3-CH2CHCH 2)][CH2 = CHCH2B(C6F 5)3] (8).
