Institut für Anorganische Chemie, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany.
Chemistry. 2009 Nov 9;15(44):11937-47. doi: 10.1002/chem.200901616.
Monocationic bis-allyl complexes Ln(eta(3)-C(3)H(5))(2)(thf)(3)B(C(6)X(5))(4) (Ln = Y, La, Nd; X = H, F) and dicationic mono-allyl complexes of yttrium and the early lanthanides Ln(eta(3)-C(3)H(5))(thf)(6)BPh(4)(-) (Ln = La, Nd) were prepared by protonolysis of the tris-allyl complexes [Ln(eta(3)-C(3)H(5))(3)(diox)] (Ln = Y, La, Ce, Pr, Nd, Sm; diox = 1,4-dioxane) isolated as a 1,4-dioxane-bridged dimer (Ln = Ce) or THF adducts [Ln(eta(3)-C(3)H(5))(3)(thf)(2)] (Ln = Ce, Pr). Allyl abstraction from the neutral tris-allyl complex by a Lewis acid, ER(3) (Al(CH(2)SiMe(3))(3), BPh(3)) gave the ion pair Ln(eta(3)-C(3)H(5))(2)(thf)(3)ER(3)(eta(1)-CH(2)CH=CH(2)) (Ln = Y, La; ER(3) = Al(CH(2)SiMe(3))(3), BPh(3)). Benzophenone inserts into the La-C(allyl) bond of La(eta(3)-C(3)H(5))(2)(thf)(3)BPh(4) to form the alkoxy complex La{OCPh(2)(CH(2)CH=CH(2))}(2)(thf)(3)BPh(4). The monocationic half-sandwich complexes Ln(eta(5)-C(5)Me(4)SiMe(3))(eta(3)-C(3)H(5))(thf)(2)B(C(6)X(5))(4) (Ln = Y, La; X = H, F) were synthesized from the neutral precursors [Ln(eta(5)-C(5)Me(4)SiMe(3))(eta(3)-C(3)H(5))(2)(thf)] by protonolysis. For 1,3-butadiene polymerization catalysis, the yttrium-based systems were more active than the corresponding lanthanum or neodymium homologues, giving polybutadiene with approximately 90% 1,4-cis stereoselectivity.
单阳离子双烯丙基配合物 Ln(eta(3)-C(3)H(5))(2)(thf)(3)B(C(6)X(5))(4)（Ln = Y，La，Nd；X = H，F）和单阳离子单烯丙基配合物钇和早期镧系元素 Ln(eta(3)-C(3)H(5))(thf)(6)BPh(4)(-)（Ln = La，Nd）通过质子解[Ln(eta(3)-C(3)H(5))(3)(diox)]（Ln = Y，La，Ce，Pr，Nd，Sm；diox = 1,4-二氧六环）制备，该配合物作为 1,4-二氧六环桥联二聚体（Ln = Ce）或 THF 加合物 [Ln(eta(3)-C(3)H(5))(3)(thf)(2)]（Ln = Ce，Pr）分离。路易斯酸 ER(3)（Al(CH(2)SiMe(3))(3)，BPh(3)）从中性三烯丙基配合物中抽走烯丙基，生成离子对 Ln(eta(3)-C(3)H(5))(2)(thf)(3)ER(3)(eta(1)-CH(2)CH=CH(2))（Ln = Y，La；ER(3) = Al(CH(2)SiMe(3))(3)，BPh(3)）。二苯甲酮插入 La(eta(3)-C(3)H(5))(2)(thf)(3)BPh(4)中的 La-C(allyl)键，形成烷氧基配合物 La{OCPh(2)(CH(2)CH=CH(2))}(2)(thf)(3)BPh(4)。单阳离子半三明治配合物 Ln(eta(5)-C(5)Me(4)SiMe(3))(eta(3)-C(3)H(5))(thf)(2)B(C(6)X(5))(4)（Ln = Y，La；X = H，F）由中性前体 [Ln(eta(5)-C(5)Me(4)SiMe(3))(eta(3)-C(3)H(5))(2)(thf)] 通过质子解制备。对于 1,3-丁二烯聚合催化，基于钇的体系比相应的镧系或钕同系物更具活性，得到具有约 90%1,4-顺式立体选择性的聚丁二烯。
