The alkoxo compounds [TaCp*Me-3(OR)] (R = SiiPr(3), 1a; 2,6-Me2C6H3, 1b; 2,6-iPr(2)C(6)H(3), 1c) were obtained by reaction of [TaCp*Me-4] with the corresponding alcohol ROH, at room temperature for R = SiiPr(3) and upon heating at 100 degrees C over 2 and 3 days for R = 2,6-Me2C6H3 and 2,6-iPr(2)C(6)H(3), respectively. The alkoxo cations [TaCp*Me-2(OR)](+) (R = SiiPr(3), 2a; 2,6-Me2C6H3, 2b; 2,6-iPr(2)C(6)H(3), 2c) were formed when one of the methyl groups of the neutral trimethyl complexes 1 was dissociated by reaction with 1 equiv of B(C6F5)(3) to generate the borate anion [MeB(C6F5)(3)](-) (B) and with 1 and 2 equiv of Al(C6F5)(3) to give the mononuclear [MeAl(C6F5)(3)](-) (Al) and dinuclear [Me{Al(C6F5)(3)}(2)](-) (Al2) aluminate anions, respectively. A similar reaction of the neutral compound [TaCp*Me-4] with 1 and 2 equiv of Al(C6F5)(3) gave salts of the [MeAl(C6F5)(3)](-) (Al) and [Me{Al(C6F5)(3)}(2)](-) (Al2) anions containing the [TaCp*Me-3](+) (3) cation. Compounds 1 and [TaCp*Me-4] did not show catalytic activity for MMA polymerization when B(C6F5)(3) was used as cocatalyst but were active in the presence of Al(C6F5)(3), yielding high molecular weight syndiotactic PMMA.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据