Department of Chemistry, Queen's University, Kingston, ON, CanadaK7L 3N6.
Dalton Trans. 2009 Nov 7(41):8864-77. doi: 10.1039/b908726e. Epub 2009 Aug 14.
Copolymerization of ethylene and propylene with polar monomers of the types CH(2)=CH(CH(2))(n)OH (n = 1-12) in order to introduce polar functionality into the resulting polymers is possible in principle if the hydroxyl groups of the polar monomers are masked such that they cannot coordinate to Lewis acidic catalyst sites and prevent eta(2)-alkene coordination. Although the use of hydrolysable ethers of the types CH(2)=CH(CH(2))(n)OR (R = alkyl, silyl; n = 1-12) is a protecting group strategy, which has been investigated somewhat, in fact this approach has not been investigated systematically and little is known of the effectiveness of various R groups in hindering oxygen coordination to e.g. metallocene polymerization catalyst systems. We report here the results (a) of an NMR study of reactions of an archetypal metallocene polymerization catalyst, Cp(2)ZrMe(mu-Me)B(C(6)F(5))(3), with the polar monomers CH(2)=CH(CH(2))(8)OR (R = Me, PhCH(2), Ph(3)C, Me(3)Si, Ph(3)Si), all protected versions of the readily available, long chain polar monomer 9-decen-1-ol, and (b) of an investigation of the copolymerization reactions of these same polar monomers with ethylene and propylene catalyzed by the well known rac-C(2)H(4)(Ind)(2)ZrCl(2)/MAO catalyst system. While increasing the steric requirements of the groups R does decrease the apparent abilities of the ethers to displace BMe(C(6)F(5))(3) from the Cp(2)ZrMe cation, there is no correlation of size of R with the degrees of incorporation of the polar monomers into copolymers of ethylene and propylene. Instead, a heretofore unsuspected role for catalyst activation by the ether linkage is suggested.
共聚单体的乙烯和丙烯与极性单体的类型 ch(2)=ch(ch(2))(n)oh(n = 1-12)引入极性功能到聚合物是可能的原则上如果羟基的极性单体被屏蔽使得它们不能协调到路易斯酸性催化剂位点和防止 eta(2)-烯配位。虽然使用可水解醚的类型 ch(2)=ch(ch(2))(n)or(r = 烷基,硅烷基;n = 1-12)是一种保护基团的策略,这已经被研究了一些,事实上,这种方法没有进行系统的研究和知道的很少的各种 r 组的有效性在阻碍氧协调例如茂金属聚合催化剂体系。我们在这里报告的结果(a)一个核磁共振研究反应的一个原型茂金属聚合催化剂,cp(2)zrme(mu-me)b(c(6)f(5))(3),与极性单体 ch(2)=ch(ch(2))(8)or(r = 甲基,苯甲基,三苯甲基,甲基,三甲基硅基),所有受保护的版本很容易获得的长链极性单体 9-癸烯-1-醇,和(b)的共聚反应的这些相同的极性单体与乙烯和丙烯催化的知名 rac-c(2)h(4)(ind)(2)zrcl(2)/mao 催化剂体系。而增加空间位阻的要求 r 组确实降低了醚的能力取代bme(c(6)f(5))(3)从c p(2)zrme阳离子,没有相关性的大小与 r 程度的纳入极性单体到共聚物的乙烯和丙烯。相反,一个以前没有怀疑的作用的醚键催化剂的激活。