Synthesis of β-diketiminate-ligated bimetallic and monometallic lanthanide amide complexes and their reactivity with isoprene and AlMe3
作者:Song Sun、Hao Ouyang、Yunjie Luo、Yong Zhang、Qi Shen、Yingming Yao
DOI:10.1039/c3dt52014e
日期:——
The amine elimination of lanthanide tris(amide) complexes with the phenylene-bridged bis(β-diketiminate) ligands PARAMe-H2, METAMe-H2 and PARAPr-H2 (PARAMe-H2 = 2[2,6-Me2C6H3NHC(Me)C(H)C(Me)N]-(para-phenylene), METAMe-H2 = 2[2,6-Me2C6H3NHC(Me)C(H)C(Me)N]-(meta-phenylene), PARAPr-H2 = 2[2,6-iPr2C6H3NHC(Me)C(H)C(Me)N]-(para-phenylene)), and the mono-β-diketiminate ligand L2,6-iPr2Ph-H (2,6-iPr2C6H3)NHC(Me)CHC(Me)N(C6H5)) afforded the bimetallic lanthanide amide complexes PARAMe-Ln[N(SiMe3)2]2}2 (Ln = Y (1), Sm (2)), METAMe-Y[N(SiMe3)2]2}2 (3), PARAPr-Ln[N(HSiMe2)2]2}2 (Ln = Y (4), Sm (5)), and the monomeric complexes L2,6-iPr2Ph-Y[N(SiMe3)2]2 (6) and L2,6-iPr2Ph-Y[N(HSiMe2)2]2 (7). In the presence of AlR3 and on activation with 1 equiv. of [Ph3C][B(C6F5)4], complexes 1â7 showed a high activity toward the 1,4-selective polymerization of isoprene. The heterometallic Y/Al methyl complex [L2,6-iPr2Ph]Y[(μ-Me)2AlMe2]2 (8) was prepared to elucidate the real active precursor in the polymerization.
具有芳基桥接双(β-二酮亚胺)配体PARAMe-H2、METAMe-H2和PARAPr-H2的镧系金属三(酰胺)配合物的胺消除反应(PARAMe-H2 = 2[2,6-Me2C6H3NHC(Me)C(H)C(Me)N]-(对位苯),METAMe-H2 = 2[2,6-Me2C6H3NHC(Me)C(H)C(Me)N]-(间位苯),PARAPr-H2 = 2[2,6-iPr2C6H3NHC(Me)C(H)C(Me)N]-(对位苯)以及单β-二酮亚胺配体L2,6-iPr2Ph-H (2,6-iPr2C6H3)NHC(Me)CHC(Me)N(C6H5)),得到双金属镧系金属酰胺配合物PARAMe-Ln[N(SiMe3)2]2}2 (Ln = Y (1), Sm (2))、METAMe-Y[N(SiMe3)2]2}2 (3)、PARAPr-Ln[N(HSiMe2)2]2}2 (Ln = Y (4), Sm (5)),以及单体配合物L2,6-iPr2Ph-Y[N(SiMe3)2]2 (6)和L2,6-iPr2Ph-Y[N(HSiMe2)2]2 (7)。在AlR3存在的条件下,使用1当量[Ph3C][B(C6F5)4]激活后,复合物1–7表现出对异戊二烯1,4-选择性聚合的高活性。为阐明聚合中的真实活性前驱体,合成了异金属Y/Al甲基复合物[L2,6-iPr2Ph]Y[(μ-Me)2AlMe2]2 (8)。