The products of the reactions of polymethylalumoxane (MAO) with triisobutylaluminum (TIBA), rac-Me2Si(2-Me,4-PhInd)2ZrCl2 (1) with MAO (1 + MAO), and (1 + MAO) + TIBA were studied by 1H NMR at different molar ratios of the components. When the ratio AlTIBA/AlMAO is ∼6, the reaction between MAO and TIBA involves the replacement of the methyl group of MAO by isobutyl groups and the formation of isobutylmethylalumoxane or mixed isobutylmethylalumoxane structures. When the TIBA content in the system increases to 30 mol.%, these structures are rearranged to form products with a low degree of association. With the equimolar ratio of the reactants, the main reaction products are tetraisobutylalumoxane and polyisobutylalumoxane. The 1 + MAO system with the molar ratio AlMAO/Zr = 50 affords a MAO-bonded monomethyl monochloride derivative [L2ZrCl-µ-Me]δ+[MAO]δ−. An increase in this ratio to 150 produces intermediate binuclear complexes [L2ZrCl-µ-Me-MeZrL2]+[MAO]− and [Me2Al-(µ-Me)2-ZrL2]+[MAO]−. The addition of TIBA induces the replacement of the ZrMe groups by isobutyl groups at the first step of the interaction and formation of nonidentified reaction products at the subsequent steps.
用 1H NMR 研究了聚甲基铝氧烷(MAO)与
三异丁基铝(T
IBA)、rac-Me2Si(2-Me,4-PhInd)2ZrC
L2 (1) 与 MAO (1 + MAO) 以及 (1 + MAO) + T
IBA 在不同摩尔比下的反应产物。当 AlT
IBA/AlMAO 的比例为 ∼6 时,MAO 和 T
IBA 的反应涉及异丁基取代 MAO 的甲基,并形成异丁基甲基铝氧烷或异丁基甲基铝氧烷混合结构。当体系中的 T
IBA 含量增加到 30 摩尔%时,这些结构会重新排列,形成关联度较低的产物。在反应物比例相等的情况下,主要的反应产物是四异丁基铝氧烷和聚异丁基铝氧烷。摩尔比为 AlMAO/Zr = 50 的 1 + MAO 体系会产生 MAO 键合的单甲基一
氯化物衍
生物 [
L2ZrCl-µ-Me]δ+[MAO]δ-。将这一比例提高到 150 会产生中间双核配合物 [
L2ZrCl-µ-Me-MeZr
L2]+[MAO]- 和 [Me2Al-(µ-Me)2-Zr
L2]+[MAO]-。在相互作用的第一步,T
IBA 的加入会促使 ZrMe 基团被异丁基取代,并在随后的步骤中形成未识别的反应产物。